Colorectal cancer Classification and external resources
Diagram of the stomach, colon, and rectum
ICD-10	C18.-C20.
ICD-9	153.0-154.1
ICD-O:	M8140/3 (95% of cases)
OMIM	114500
DiseasesDB	2975
MedlinePlus	000262
eMedicine	med/413  med/1994 ped/3037

Gross appearance of a colectomy specimen containing two adenomatous polyps (the brownish oval tumors above the labels, attached to the normal beige lining by a stalk) and one invasive colorectal carcinoma (the crater-like, reddish, irregularly-shaped tumor located above the label). The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The International Classification of Diseases for Oncology (ICD-O is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems The International Classification of Diseases for Oncology (ICD-O is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Gross examination or "grossing" is the process by which Pathology specimens are inspected with the naked eye to obtain diagnostic information while being Colectomy consists of the surgical Resection of any extent of the large intestine ( colon) A colorectal polyp (or colon polyp) is a fleshy growth ( polyp) occurring on the lining of the Colon or Rectum.

Gross appearance of a colectomy specimen containing one invasive colorectal carcinoma (the crater-like, reddish, irregularly-shaped tumor). Gross examination or "grossing" is the process by which Pathology specimens are inspected with the naked eye to obtain diagnostic information while being Colectomy consists of the surgical Resection of any extent of the large intestine ( colon)

Colorectal cancer, also called colon cancer or large bowel cancer, includes cancerous growths in the colon, rectum and appendix. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled The colon is a storage tube for solid wastes The main function of the colon appears to be extraction of Water and salts from Feces. The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the Large intestine in some Mammals In Human anatomy, the appendix (or vermiform appendix; also cecal (or caecal appendix; also vermix) is a blind ended tube connected to the It is the third most common form of cancer and the second leading cause of cancer-related death in the Western world. Colorectal cancer causes 655,000 deaths worldwide per year, including about 16,000 in the UK, where it is the second most common site (after lung) to cause cancer death. ^[1] Many colorectal cancers are thought to arise from adenomatous polyps in the colon. An adenoma is a collection of growths (-oma of glandular origin A colorectal polyp (or colon polyp) is a fleshy growth ( polyp) occurring on the lining of the Colon or Rectum. These mushroom-like growths are usually benign, but some may develop into cancer over time. The majority of the time, the diagnosis of localized colon cancer is through colonoscopy. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic Therapy is usually through surgery, which in many cases is followed by chemotherapy. Chemotherapy, in its most general sense refers to treatment of disease by chemicals that kill cells specifically those of micro-organisms or Cancer.

Symptoms

The first symptoms of colon cancer are usually vague, like weight loss and fatigue (tiredness). Local (bowel) symptoms are rare until the tumor has grown to a large size. Generally, the nearer the tumor is to the anus, the more bowel symptoms there will be. The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth.

Symptoms and signs are divided into local, constitutional and metastatic.

Local symptoms

• Change in bowel habits
  • Change in frequency (constipation and/or diarrhea),
  • Feeling of incomplete defecation (tenesmus) and reduction in diameter of stool, both characteristic of rectal cancer,
  • Change in the appearance of stools :
    • Bloody stools or rectal bleeding
    • Stools with mucus
    • Black, tar-like stool (melena), more likely related to upper gastrointestinal eg stomach or duodenal disease
• Bowel obstruction causing bowel pain, bloating and vomiting of stool-like material. Constipation, costiveness, or irregularity, is a condition of the Digestive system in which a person (or animal experiences hard Feces that In Medicine, diarrhea, also spelled diarrhoea (see spelling differences) is frequent loose or liquid Bowel movements Acute diarrhea Tenesmus is a feeling of incomplete Defecation. It is experienced as an inability or difficulty to empty the bowel at Defecation. Hematochezia is the passage of bright red Bloody stools from the Rectum. In vertebrates mucus is a slippery secretion produced by and covering Mucous membranes It is a viscous Colloid containing Antiseptic enzymes (such as In Medicine, melena or melaena refers to the black "tarry" Feces that are associated with gastrointestinal Hemorrhage. Bowel obstruction (or intestinal obstruction) is a mechanical or functional obstruction of the intestines preventing the normal transit of the products of digestion
• A tumor in the abdomen, felt by patients or their doctors. See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic
• Symptoms related to invasion by the cancer of the bladder causing hematuria (blood in the urine) or pneumaturia (air in the urine), or invasion of the vagina causing smelly vaginal discharge. In Anatomy, the urinary bladder is a hollow muscular, and distensible (or elastic organ that sits on the Pelvic floor in Mammals It is the In Medicine, hematuria (or "haematuria" is the presence of Red blood cells (erythrocytes in the Urine. Pneumaturia is the passage of Gas or "air" in Urine. This may be seen or described as "bubbles in the urine" The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus These are late events, indicative of a large tumor.

Constitutional (systemic) symptoms

• Unexplained weight loss, probably the most common symptom, caused by lack of appetite
• Anemia, causing dizziness, fatigue and palpitations. Anorexia (deriving from the Greek "α(ν-" ( a(n-, a prefix that denotes absence + "όρεξη (orexe = appetite is the decreased sensation Anemia ( AmE) or anæmia/anaemia ( BrE) (from the Ancient Greek grc-Latn anaîmia, meaning “without blood” is defined as a qualitative A palpitation (medical term ectopic heart beat) is an abnormal awareness of the beating of the Heart, whether it is too slow too fast irregular Clinically, there will be pallor and blood tests will confirm the low hemoglobin level. Pallor (also called pastiness or wanness) is a reduced amount of oxy Hemoglobin in Skin or Mucous membrane, a pale color which can

Metastatic symptoms

• Liver metastases, causing :
  • Jaundice. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets, Jaundice, also known as icterus (attributive adjective "icteric" is yellowish discoloration of the Skin, sclerae (whites of the eyes
  • Pain in the abdomen, more often the upper part (epigastrium or right side of the abdomen
  • liver enlargement, usually felt by a doctor. In Vertebrates such as Mammals the abdomen (belly constitutes the part of the body between the Thorax (chest and Pelvis. The epigastrium (or epigastric region) is the upper central region of the Abdomen. Hepatomegaly is the condition of having an enlarged Liver. It is a nonspecific medical sign having many causes which can broadly be broken down into Infection
• Blood clots in the veins and arteries, a paraneoplastic syndrome related to hypercoagulability of the blood (the blood is "thickened")

Risk factors

The lifetime risk of developing colon cancer in the United States is about 7%. A thrombus, or blood clot, is the final product of the Blood coagulation step in Hemostasis. A paraneoplastic syndrome is a Disease or Symptom that is the consequence of the presence of Cancer in the body but is not due to the local presence Thrombophilia is the propensity to develop Thrombosis (blood clots due to an abnormality in the system of Coagulation. Certain factors increase a person's risk of developing the disease. These include:

• Age. The risk of developing colorectal cancer increases with age. Most cases occur in the 60s and 70s, while cases before age 50 are uncommon unless a family history of early colon cancer is present.
• Polyps of the colon, particularly adenomatous polyps, are a risk factor for colon cancer. A colorectal polyp (or colon polyp) is a fleshy growth ( polyp) occurring on the lining of the Colon or Rectum. The removal of colon polyps at the time of colonoscopy reduces the subsequent risk of colon cancer.
• History of cancer. Individuals who have previously been diagnosed and treated for colon cancer are at risk for developing colon cancer in the future. Women who have had cancer of the ovary, uterus, or breast are at higher risk of developing colorectal cancer.
• Heredity:
  • Family history of colon cancer, especially in a close relative before the age of 55 or multiple relatives
  • Familial adenomatous polyposis (FAP) carries a near 100% risk of developing colorectal cancer by the age of 40 if untreated
  • Hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome
• Long-standing ulcerative colitis or Crohn's disease of the colon, approximately 30% after 25 years if the entire colon is involved
• Smoking. Familial adenomatous polyposis ( FAP) is an inherited condition in which numerous polyps form mainly in the Epithelium of the large intestine. Hereditary nonpolyposis colorectal cancer (HNPCC also known as Lynch syndrome, is characterised by a risk of Colorectal cancer and other cancers of the endometrium Ulcerative colitis ( Colitis ulcerosa, UC) is a form of Inflammatory bowel disease (IBD Crohn's disease is a Disease of the Digestive system which may affect any part of the Gastrointestinal tract from Mouth to Anus Smokers are more likely to die of colorectal cancer than non-smokers. An American Cancer Society study found that "Women who smoked were more than 40% more likely to die from colorectal cancer than women who never had smoked. The American Cancer Society ( ACS) is the "nationwide community-based voluntary health organization dedicated to Male smokers had more than a 30% increase in risk of dying from the disease compared to men who never had smoked. "^[2]
• Diet. Studies show that a diet high in red meat^[3] and low in fresh fruit, vegetables, poultry and fish increases the risk of colorectal cancer. In June 2005, a study by the European Prospective Investigation into Cancer and Nutrition suggested that diets high in red and processed meat, as well as those low in fiber, are associated with an increased risk of colorectal cancer. The European Prospective Investigation into Cancer and Nutrition (EPIC study is a Europe -wide prospective Cohort study of the relationships between diet Individuals who frequently eat fish showed a decreased risk. [1] However, other studies have cast doubt on the claim that diets high in fiber decrease the risk of colorectal cancer; rather, low-fiber diet was associated with other risk factors, leading to confounding. ^[4] The nature of the relationship between dietary fiber and risk of colorectal cancer remains controversial.
• Physical inactivity. People who are physically active are at lower risk of developing colorectal cancer.
• Virus. Exposure to some viruses (such as particular strains of human papilloma virus) may be associated with colorectal cancer. A human papillomavirus ( HPV) is a Papillomavirus that infects the skin and Mucous membranes of Humans Approximately 130 HPV types have been
• Alcohol. See the subsection below.
• Primary sclerosing cholangitis offers a risk independent to ulcerative colitis
• Low selenium. Primary sclerosing cholangitis ( PSC) is a chronic liver disease caused by progressive Inflammation and scarring of the Bile ducts of the liver Ulcerative colitis ( Colitis ulcerosa, UC) is a form of Inflammatory bowel disease (IBD Selenium (səˈliniəm is a Chemical element with the Atomic number 34 represented by the chemical symbol Se, an atomic mass of 78
• Inflammatory Bowel Disease. ^{[5] [6]} About one percent of colorectal cancer patients have a history of chronic ulcerative colitis. The risk of developing colorectal cancer varies inversely with the age of onset of the colitis and directly with the extent of colonic involvement and the duration of active disease. Patients with colorectal Crohn's disease have a more than average risk of colorectal cancer, but less than that of patients with ulcerative colitis. ^[7]
• Environmental Factors. ^[5] Industrialized countries are at a relatively increased risk compared to less developed countries or countries that traditionally had high-fiber/low-fat diets. Studies of migrant populations have revealed a role for environmental factors, particularly dietary, in the etiology of colorectal cancers. Genetic factors and inflammatory bowel disease also place certain individuals at increased risk. ^[8]
• Exogenous Hormones. The differences in the time trends in colorectal cancer in males and females could be explained by cohort effects in exposure to some sex-specific risk factor; one possibility that has been suggested is exposure to estrogens ^[9]. There is, however, little evidence of an influence of endogenous hormones on the risk of colorectal cancer. In contrast,there is evidence that exogenous estrogens such as hormone replacement therapy (HRT), tamoxifen, or oral contraceptives might be associated with colorectal tumors. ^[10]

Alcohol

The WCRF panel report Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective finds the evidence "convincing" that alcoholic drinks increase the risk of colorectal cancer in men. ^[11]

The NIAAA reports that: "Epidemiologic studies have found a small but consistent dose-dependent association between alcohol consumption and colorectal cancer^[12][13]even when controlling for fiber and other dietary factors. ^[14][15] Despite the large number of studies, however, causality cannot be determined from the available data. "^[16]

"Heavy alcohol use may also increase the risk of colorectal cancer" (NCI). One study found that "People who drink more than 30 grams of alcohol per day (and especially those who drink more than 45 grams per day) appear to have a slightly higher risk for colorectal cancer. "^[17][18] Another found that "The consumption of one or more alcoholic beverages a day at baseline was associated with approximately a 70% greater risk of colon cancer. "^[19][20][21]

One study found that "While there was a more than twofold increased risk of significant colorectal neoplasia in people who drink spirits and beer, people who drank wine had a lower risk. In our sample, people who drank more than eight servings of beer or spirits per week had at least a one in five chance of having significant colorectal neoplasia detected by screening colonoscopy. ". ^[22]

Other research suggests that "to minimize your risk of developing colorectal cancer, it's best to drink in moderation"^[16]

On its colorectal cancer page, the National Cancer Institute does not list alcohol as a risk factor^[23]: however, on another page it states, "Heavy alcohol use may also increase the risk of colorectal cancer" ^[24]

Drinking may be a cause of earlier onset of colorectal cancer. The National Cancer Institute (NCI is part of the United States Federal government's National Institutes of Health. ^[25]

Diagnosis, screening and monitoring

Endoscopic image of colon cancer identified in sigmoid colon on screening colonoscopy in the setting of Crohn's disease. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic The colon is a storage tube for solid wastes The main function of the colon appears to be extraction of Water and salts from Feces. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic Crohn's disease is a Disease of the Digestive system which may affect any part of the Gastrointestinal tract from Mouth to Anus

Colorectal cancer can take many years to develop and early detection of colorectal cancer greatly improves the chances of a cure. Therefore, screening for the disease is recommended in individuals who are at increased risk. There are several different tests available for this purpose.

• Digital rectal exam (DRE): The doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas. A rectal examination or rectal exam is an internal examination of the Rectum such as by a Physician or other healthcare professional It only detects tumors large enough to be felt in the distal part of the rectum but is useful as an initial screening test.
• Fecal occult blood test (FOBT): a test for blood in the stool. Faecal occult blood is a term for Blood present in the Faeces that is not visibly apparent Two types of tests can be used for detecting occult blood in stools i. e. guaiac based (chemical test) and immunochemical. The sensitivity of immunochemical testing is superior to that of chemical testing without an unacceptable reduction in specifity. ^[26]
• Endoscopy:
  • Sigmoidoscopy: A lighted probe (sigmoidoscope) is inserted into the rectum and lower colon to check for polyps and other abnormalities. Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an instrument called an endoscope. Sigmoidoscopy is the Minimally invasive medical examination of the large Intestine from the Rectum through the last part of the colon
  • Colonoscopy: A lighted probe called a colonoscope is inserted into the rectum and the entire colon to look for polyps and other abnormalities that may be caused by cancer. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic A polyp is an abnormal growth of tissue ( Tumor) projecting from a Mucous membrane. A colonoscopy has the advantage that if polyps are found during the procedure they can be immediately removed. A polyp is an abnormal growth of tissue ( Tumor) projecting from a Mucous membrane. Tissue can also be taken for biopsy. A biopsy (in Greek: βίος life and όψη look/appearance is a Medical test involving the removal of cells or tissues

In the United States, colonoscopy or FOBT plus sigmoidoscopy are the preferred screening options.

Other screening methods

• Double contrast barium enema (DCBE): First, an overnight preparation is taken to cleanse the colon. An enema containing barium sulfate is administered, then air is insufflated into the colon, distending it. An enema (plural enemata or enemas) is the procedure of introducing liquids into the Rectum and colon via the Anus. Barium sulfate is a white crystalline solid with the chemical formula BaSO4 The result is a thin layer of barium over the inner lining of the colon which is visible on X-ray films. A cancer or a precancerous polyp can be detected this way. This technique can miss the (less common) flat polyp.
• Virtual colonoscopy replaces X-ray films in the double contrast barium enema (above) with a special computed tomography scan and requires special workstation software in order for the radiologist to interpret. Virtual colonoscopy (VC is a Medical imaging procedure which uses X-rays and Computers to produce two- and three-dimensional images of the Computed tomography (CT is a Medical imaging method employing Tomography. Radiology is the medical specialty directing Medical imaging technologies to diagnose and treat diseases This technique is approaching colonoscopy in sensitivity for polyps. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic However, any polyps found must still be removed by standard colonoscopy.
• Standard computed axial tomography is an x-ray method that can be used to determine the degree of spread of cancer, but is not sensitive enough to use for screening. Computed tomography (CT is a Medical imaging method employing Tomography. Some cancers are found in CAT scans performed for other reasons.
• Blood tests: Measurement of the patient's blood for elevated levels of certain proteins can give an indication of tumor load. A blood test is a laboratory analysis performed on a Blood sample that is usually extracted from a Vein in the arm using a needle, or via Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In particular, high levels of carcinoembryonic antigen (CEA) in the blood can indicate metastasis of adenocarcinoma. Carcinoembryonic antigen (CEA is a Glycoprotein involved in Cell adhesion. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets, Adenocarcinoma is a cancer that originates in Glandular tissue These tests are frequently false positive or false negative, and are not recommended for screening, it can be useful to assess disease recurrence. In Statistics, the terms Type I error (also α error, or false positive) and type II error ( β error, or a false negative In Statistics, the terms Type I error (also α error, or false positive) and type II error ( β error, or a false negative
• Genetic counseling and genetic testing for families who may have a hereditary form of colon cancer, such as hereditary nonpolyposis colorectal cancer (HNPCC) or familial adenomatous polyposis (FAP). Genetic counseling is the process by which patients or relatives at risk of an inherited disorder are advised of the consequences and nature of the disorder the probability of developing Genetic testing allows the genetic Diagnosis of vulnerabilities to inherited Diseases, and can also be used to determine a person's Ancestry. Hereditary nonpolyposis colorectal cancer (HNPCC also known as Lynch syndrome, is characterised by a risk of Colorectal cancer and other cancers of the endometrium Familial adenomatous polyposis ( FAP) is an inherited condition in which numerous polyps form mainly in the Epithelium of the large intestine.
• Positron emission tomography (PET) is a 3-dimensional scanning technology where a radioactive sugar is injected into the patient, the sugar collects in tissues with high metabolic activity, and an image is formed by measuring the emission of radiation from the sugar. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the Because cancer cells often have very high metabolic rate, this can be used to differentiate benign and malignant tumors. PET is not used for screening and does not (yet) have a place in routine workup of colorectal cancer cases.
• Whole-Body PET imaging is the most accurate diagnostic test for detection of recurrent colorectal cancer, and is a cost-effective way to differentiate resectable from non-resectable disease. A PET scan is indicated whenever a major management decision depends upon accurate evaluation of tumour presence and extent.
• Stool DNA testing is an emerging technology in screening for colorectal cancer. Pre-malignant adenomas and cancers shed DNA markers from their cells which are not degraded during the digestive process and remain stable in the stool. Capture, followed by PCR amplifies the DNA to detectable levels for assay. Clinical studies have shown a cancer detection sensitivity of 71%-91%. ^[27]

Pathology

Histopathologic image of colonic carcinoid stained by hematoxylin and eosin.

The pathology of the tumor is usually reported from the analysis of tissue taken from a biopsy or surgery. Pathology (from Greek grc πάθος pathos, "fate harm" and grc -λογία -logia) is the study and See also Cancer A tumor or tumour is the name for a swelling or lesion formed by an abnormal growth of cells (termed neoplastic A pathology report will usually contain a description of cell type and grade. Histology (from the Greek = 'tissue' is the study of the microscopic anatomy of cells and tissues of Plants and The most common colon cancer cell type is adenocarcinoma which accounts for 95% of cases. Adenocarcinoma is a cancer that originates in Glandular tissue Other, rarer types include lymphoma and squamous cell carcinoma. Lymphoma a type of Neoplasm that originates in Lymphocytes (a type of White blood cell in the vertebrate Immune system) In Medicine, squamous cell carcinoma (SCC is a form of Cancer of the Carcinoma type that may occur in many different organs including the Skin

Cancers on the right side (ascending colon and cecum) tend to be exophytic, that is, the tumour grows outwards from one location in the bowel wall. The cecum or caecum (from the Latin caecus meaning Blind) is a pouch connected to the Ascending colon of the Large This very rarely causes obstruction of feces, and presents with symptoms such as anemia. Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus Anemia ( AmE) or anæmia/anaemia ( BrE) (from the Ancient Greek grc-Latn anaîmia, meaning “without blood” is defined as a qualitative Left-sided tumours tend to be circumferential, and can obstruct the bowel much like a napkin ring.

Histopathology: Adenocarcinoma is a malignant epithelial tumor, originating from glandular epithelium of the colorectal mucosa. It invades the wall, infiltrating the muscularis mucosae, the submucosa and thence the muscularis propria. The lamina muscularis mucosae (or "muscularis mucosa" is the thin layer of Smooth muscle found in most parts of the Gastrointestinal tract, located In the Gastrointestinal tract, the submucosa is the layer of Loose connective tissue that supports the Mucosa, as well as joins the mucosa to the bulk Tumor cells describe irregular tubular structures, harboring pluristratification, multiple lumens, reduced stroma ("back to back" aspect). Sometimes, tumor cells are discohesive and secrete mucus, which invades the interstitium producing large pools of mucus/colloid (optically "empty" spaces) - mucinous (colloid) adenocarcinoma, poorly differentiated. If the mucus remains inside the tumor cell, it pushes the nucleus at the periphery - "signet-ring cell. " Depending on glandular architecture, cellular pleomorphism, and mucosecretion of the predominant pattern, adenocarcinoma may present three degrees of differentiation: well, moderately, and poorly differentiated. ^[28]

Staging

Colon cancer staging is an estimate of the amount of penetration of a particular cancer. The stage of a cancer is a descriptor (usually numbers I to IV of how much the Cancer has spread It is performed for diagnostic and research purposes, and to determine the best method of treatment. The systems for staging colorectal cancers largely depend on the extent of local invasion, the degree of lymph node involvement and whether there is distant metastasis. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets,

Definitive staging can only be done after surgery has been performed and pathology reports reviewed. Colectomy consists of the surgical Resection of any extent of the large intestine ( colon) An exception to this principle would be after a colonoscopic polypectomy of a malignant pedunculated polyp with minimal invasion. Preoperative staging of rectal cancers may be done with endoscopic ultrasound. Endoscopic ultrasound is a medical procedure in which an endoscopically directed Ultrasound is used to obtain images of the internal organs in the Adjuncts to staging of metastasis include Abdominal Ultrasound, CT, PET Scanning, and other imaging studies. Computed tomography (CT is a Medical imaging method employing Tomography. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the

Dukes system

Dukes classification, first proposed by Dr Cuthbert E. In 1932 The British Pathologist Dr Cuthbert Dukes (1890-1977 devised a famous Classification system for Colorectal cancer which is still in use today (albeit in several Dukes in 1932, identifies the stages as:^[29]

• A - Tumour confined to the intestinal wall
• B - Tumour invading through the intestinal wall
• C - With lymph node(s) involvement
• D - With distant metastasis

TNM system

Main article: TNM

The most common current staging system is the TNM (for tumors/nodes/metastases) system, though many doctors still use the older Dukes system. The TNM Classification of Malignant Tumours ( TNM) is a Cancer staging system that describes the extent of Cancer in a patient’s body The TNM Classification of Malignant Tumours ( TNM) is a Cancer staging system that describes the extent of Cancer in a patient’s body The TNM system assigns a number^[30]:

• T - The degree of invasion of the intestinal wall
  • T0 - no evidence of tumor
  • Tis- cancer in situ (tumor present, but no invasion)
  • T1 - invasion through submucosa into lamina propria (basement membrane invaded)
  • T2 - invasion into the muscularis propria (i. The TNM Classification of Malignant Tumours ( TNM) is a Cancer staging system that describes the extent of Cancer in a patient’s body In the Gastrointestinal tract, the submucosa is the layer of Loose connective tissue that supports the Mucosa, as well as joins the mucosa to the bulk The muscular coat ( muscular layer, muscular fibers, muscularis propria, muscularis externa) is a region of Muscle in many organs e. proper muscle of the bowel wall)
  • T3 - invasion through the subserosa
  • T4 - invasion of surrounding structures (e. In Anatomy, a serous membrane (or serosa) is a smooth membrane consisting of a thin layer of cells which excrete Serous fluid g. bladder) or with tumour cells on the free external surface of the bowel
• N - the degree of lymphatic node involvement
  • N0 - no lymph nodes involved
  • N1 - one to three nodes involved
  • N2 - four or more nodes involved
• M - the degree of metastasis
  • M0 - no metastasis
  • M1 - metastasis present

AJCC stage groupings

The stage of a cancer is usually quoted as a number I, II, III, IV derived from the TNM value grouped by prognosis; a higher number indicates a more advanced cancer and likely a worse outcome. The lymphatic system in Vertebrates is a network of conduits that carry a clear fluid called Lymph. A Lymph node ( lɪmf noʊd is an organ consisting of many types of cells and is a part of the Lymphatic system. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets,

• Stage 0
  • Tis, N0, M0
• Stage I
  • T1, N0, M0
  • T2, N0, M0
• Stage IIA
  • T3, N0, M0
• Stage IIB
  • T4, N0, M0
• Stage IIIA
  • T1, N1, M0
  • T2, N1, M0
• Stage IIIB
  • T3, N1, M0
  • T4, N1, M0
• Stage IIIC
  • Any T, N2, M0
• Stage IV
  • Any T, Any N, M1

Pathogenesis

Colorectal cancer is a disease originating from the epithelial cells lining the gastrointestinal tract. In biology and medicine epithelium is a tissue composed of cells that line the cavities and surfaces of structures throughout the body Hereditary or somatic mutations in specific DNA sequences, among which are included DNA replication or DNA repair genes^[31], and also the APC, K-Ras, NOD2 and p53 genes, lead to unrestricted cell division. A genetic disorder is a condition caused by abnormalities in Genes or Chromosomes While some diseases such as Cancer, are due to genetic abnormalities acquired Somatic cells are any cells forming the body of an organism as opposed to Germline cells In biology mutations are changes to the Nucleotide sequence of the Genetic material of an organism Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known DNA replication is the process of copying a double-stranded DNA molecule to form two double-stranded molecules DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its Genome. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance NOD2 ( n ucleotide-binding o ligomerization d omain containing 2) is a Protein, also known as the caspase recruitment domain p53 (also known as protein 53 or tumor protein 53) is a Transcription factor encoded by the TP53 gene The exact reason why (and whether) a diet high in fiber might prevent colorectal cancer remains uncertain. Chronic inflammation, as in inflammatory bowel disease, may predispose patients to malignancy. In Medicine, inflammatory bowel disease ( IBD) is a group of inflammatory conditions of the large intestine and Small intestine

Treatment

The treatment depends on the staging of the cancer. When colorectal cancer is caught at early stages (with little spread) it can be curable. However when it is detected at later stages (when distant metastases are present) it is less likely to be curable. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets,

Surgery remains the primary treatment while chemotherapy and/or radiotherapy may be recommended depending on the individual patient's staging and other medical factors.

Surgery

Surgeries can be categorised into curative, palliative, bypass, fecal diversion, or open-and-close.

Curative Surgical treatment can be offered if the tumor is localized. Surgery (from the χειρουργική cheirourgikē, via chirurgiae meaning "hand work" is a medical specialty that uses operative manual and instrumental

• Very early cancer that develops within a polyp can often be cured by removing the polyp (i. In Zoology, a polyp is one of two forms of individuals found in many species of Cnidarians The two are the polyp or hydroid and the medusa. e. , polypectomy) at the time of colonoscopy. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic
• In colon cancer, a more advanced tumor typically requires surgical removal of the section of colon containing the tumor with sufficient margins, and radical en-bloc resection of mesentery and lymph nodes to reduce local recurrence (i. In Anatomy, the mesentery is the double layer of Peritoneum that suspends the Jejunum and Ileum from the posterior wall of the Abdomen A Lymph node ( lɪmf noʊd is an organ consisting of many types of cells and is a part of the Lymphatic system. e. , colectomy). If possible, the remaining parts of colon are anastomosed together to create a functioning colon. An anastomosis (plural anastomoses, from gr ἀναστόμωσις communicating opening) is a Network of streams that both branch out and reconnect In cases when anastomosis is not possible, a stoma (artificial orifice) is created. In Medicine, a stoma (Greek - pl stomata is an opening either natural or surgically created (artificial which connects a portion of the body cavity to the outside
• Curative surgery on rectal cancer includes total mesorectal excision (lower anterior resection) or abdominoperineal excision. Total mesorectal excision (or TME is a standard technique for treatment of Colorectal cancer, devised some 20 years ago A lower anterior resection, formally known as anterior resection of the rectum and anterior excision of the rectum or simply anterior resection, is a common An abdomino[[perineal]] resection, formally known as abdominoperineal resection of the rectum and abdominoperineal excision of the Rectum

In case of multiple metastases, palliative (non curative) resection of the primary tumor is still offered in order to reduce further morbidity caused by tumor bleeding, invasion, and its catabolic effect. In Medicine, Epidemiology and Actuarial science, the term morbidity can refer to the state of poor health (from Latin Surgical removal of isolated liver metastases is, however, common and may be curative in selected patients; improved chemotherapy has increased the number of patients who are offered surgical removal of isolated liver metastases. Chemotherapy, in its most general sense refers to treatment of disease by chemicals that kill cells specifically those of micro-organisms or Cancer.

If the tumor invaded into adjacent vital structures which makes excision technically difficult, the surgeons may prefer to bypass the tumor (ileotransverse bypass) or to do a proximal fecal diversion through a stoma. In Medicine, a stoma (Greek - pl stomata is an opening either natural or surgically created (artificial which connects a portion of the body cavity to the outside

The worst case would be an open-and-close surgery, when surgeons find the tumor unresectable and the small bowel involved; any more procedures would do more harm than good to the patient. This is uncommon with the advent of laparoscopy and better radiological imaging. Most of these cases formerly subjected to "open and close" procedures are now diagnosed in advance and surgery avoided.

Laparoscopic-assisted colectomy is a minimally-invasive technique that can reduce the size of the incision and may reduce post-operative pain. Laparoscopic surgery, also called Minimally invasive surgery (MIS, bandaid surgery, Keyhole surgery, or pinhole surgery Colectomy consists of the surgical Resection of any extent of the large intestine ( colon) Minimally invasive surgical procedures avoid open invasive surgery in favor of closed or local surgery with less trauma

As with any surgical procedure, colorectal surgery may result in complications including

• wound infection, Dehiscence (bursting of wound) or hernia
• anastomosis breakdown, leading to abscess or fistula formation, and/or peritonitis
• bleeding with or without hematoma formation
• adhesions resulting in bowel obstruction (especially small bowel)
• adjacent organ injury; most commonly to the small intestine, ureters, spleen, or bladder
• Cardiorespiratory complications such as myocardial infarction, pneumonia, arrythmia, pulmonary embolism etc

Chemotherapy

Chemotherapy is used to reduce the likelihood of metastasis developing, shrink tumor size, or slow tumor growth. An infection is the detrimental Colonization of a host Organism by a foreign Species. A hematoma, or haematoma, is a collection of Blood outside the blood vessels generally the result of Hemorrhage, or more specifically Internal bleeding Adhesions are fibrous bands that form between tissues and organs often as a result of injury during surgery Bowel obstruction (or intestinal obstruction) is a mechanical or functional obstruction of the intestines preventing the normal transit of the products of digestion Myocardial infarction ( MI or AMI for acute myocardial infarction) also known as a heart attack, occurs when the blood supply Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal Dysrhythmia redirects here For the American band see Dysrhythmia (band. Pulmonary embolism (PE is a blockage of the Pulmonary artery or one of its branches usually occurring when a venous Thrombus (blood clot from a vein Chemotherapy, in its most general sense refers to treatment of disease by chemicals that kill cells specifically those of micro-organisms or Cancer. Chemotherapy is often applied after surgery (adjuvant), before surgery (neo-adjuvant), or as the primary therapy (palliative). The treatments listed here have been shown in clinical trials to improve survival and/or reduce mortality rate and have been approved for use by the US Food and Drug Administration. In health care clinical trials are conducted to allow safety and Efficacy data to be collected for new drugs or devices In colon cancer, chemotherapy after surgery is usually only given if the cancer has spread to the lymph nodes (Stage III).

• Adjuvant (after surgery) chemotherapy. One regimen involves the combination of infusional 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX)
  • 5-fluorouracil (5-FU) or Capecitabine (Xeloda)
  • Leucovorin (LV, Folinic Acid)
  • Oxaliplatin (Eloxatin)

• Chemotherapy for metastatic disease. Fluorouracil (5-FU or f5U is a Pyrimidine analog, which is used as a drug in the treatment of Cancer. Folinic acid ( INN) or leucovorin ( USAN) generally administered as calcium folinate (or leucovorin calcium) is an Adjuvant Oxaliplatin is a Platinum -based Chemotherapy drug in the same family as Cisplatin and Carboplatin. FOLFOX is a Chemotherapy regimen for treatment of Colorectal cancer, made up of the drugs FOL– Folinic acid ( Leucovorin) Fluorouracil (5-FU or f5U is a Pyrimidine analog, which is used as a drug in the treatment of Cancer. Capecitabine ( INN) (keɪpˈsaɪtəbiːn is an orally-administered chemotherapeutic agent used in the treatment of Metastatic breast and Colorectal Folinic acid ( INN) or leucovorin ( USAN) generally administered as calcium folinate (or leucovorin calcium) is an Adjuvant Oxaliplatin is a Platinum -based Chemotherapy drug in the same family as Cisplatin and Carboplatin. Commonly used first line chemotherapy regimens involve the combination of infusional 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) with bevacizumab or infusional 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with bevacizumab
  • 5-fluorouracil (5-FU) or Capecitabine
  • Leucovorin (LV, Folinic Acid)
  • Irinotecan (Camptosar)
  • Oxaliplatin (Eloxatin)
  • Bevacizumab (Avastin)
  • Cetuximab (Erbitux)
  • Panitumumab (Vectibix)

• In clinical trials for treated/untreated metastatic disease. Chemotherapy regimens are often identified with acronyms identifying the agents used in combination Fluorouracil (5-FU or f5U is a Pyrimidine analog, which is used as a drug in the treatment of Cancer. Folinic acid ( INN) or leucovorin ( USAN) generally administered as calcium folinate (or leucovorin calcium) is an Adjuvant Oxaliplatin is a Platinum -based Chemotherapy drug in the same family as Cisplatin and Carboplatin. FOLFOX is a Chemotherapy regimen for treatment of Colorectal cancer, made up of the drugs FOL– Folinic acid ( Leucovorin) Bevacizumab (Avastin Genentech/Roche is a Monoclonal antibody against Vascular endothelial growth factor (VEGF Fluorouracil (5-FU or f5U is a Pyrimidine analog, which is used as a drug in the treatment of Cancer. Folinic acid ( INN) or leucovorin ( USAN) generally administered as calcium folinate (or leucovorin calcium) is an Adjuvant Irinotecan is a chemotherapy agent that is a topoisomerase 1 inhibitor. FOLFIRI is a Chemotherapy regimen for treatment of Colorectal cancer, made up of the drugs FOL – Folinic acid ( Leucovorin) Bevacizumab (Avastin Genentech/Roche is a Monoclonal antibody against Vascular endothelial growth factor (VEGF Fluorouracil (5-FU or f5U is a Pyrimidine analog, which is used as a drug in the treatment of Cancer. Folinic acid ( INN) or leucovorin ( USAN) generally administered as calcium folinate (or leucovorin calcium) is an Adjuvant Irinotecan is a chemotherapy agent that is a topoisomerase 1 inhibitor. Oxaliplatin is a Platinum -based Chemotherapy drug in the same family as Cisplatin and Carboplatin. Bevacizumab (Avastin Genentech/Roche is a Monoclonal antibody against Vascular endothelial growth factor (VEGF Cetuximab (IMC-C225 -- marketed under the name Erbitux) is a chimeric Monoclonal antibody, an Epidermal growth factor receptor (EGFR inhibitor Panitumumab ( INN) also ABX-EGF, is a fully human Monoclonal antibody specific to the Epidermal growth factor receptor (also known as [2]
  • Bortezomib (Velcade)
  • Oblimersen (Genasense, G3139)
  • Gefitinib and Erlotinib (Tarceva)
  • Topotecan (Hycamtin)

Radiation therapy

Radiotherapy is not used routinely in colon cancer, as it could lead to radiation enteritis, and it is difficult to target specific portions of the colon. Bortezomib (originally PS-341 and marketed as Velcade by Millennium Pharmaceuticals) is the first therapeutic Proteasome inhibitor to be tested in humans Oblimersen ( INN, trade name Genasense; also known as Augmerosen and bcl-2 antisense oligodeoxynucleotide G3139) is an antisense Gefitinib ( INN) (gɛˈfɪtɨnɪb (originally coded ZD1839 is a drug used in the treatment of certain types of Cancer. Erlotinib hydrochloride (originally coded as OSI-774) is a drug used to treat non-small cell Lung cancer, Pancreatic cancer and several other Topotecan hydrochloride (trade name Hycamtin) is a chemotherapy agent that is a topoisomerase 1 inhibitor. Radiation enteropathy or radiation enteritis is the syndrome that develops after the Intestine is exposed to Radiation. It is more common for radiation to be used in rectal cancer, since the rectum does not move as much as the colon and is thus easier to target. Indications include:

• Colon cancer
  • pain relief and palliation - targeted at metastatic tumor deposits if they compress vital structures and/or cause pain
• Rectal cancer
  • neoadjuvant - given before surgery in patients with tumors that extend outside the rectum or have spread to regional lymph nodes, in order to decrease the risk of recurrence following surgery or to allow for less invasive surgical approaches (such as a low anterior resection instead of an abdomino-perineal resection)
  • adjuvant - where a tumor perforates the rectum or involves regional lymph nodes (AJCC T3 or T4 tumors or Duke's B or C tumors)
  • palliative - to decrease the tumor burden in order to relieve or prevent symptoms

Sometimes chemotherapy agents are used to increase the effectiveness of radiation by sensitizing tumor cells if present. Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets,

Immunotherapy

Bacillus Calmette-Guérin (BCG) is being investigated as an adjuvant mixed with autologous tumor cells in immunotherapy for colorectal cancer. Bacillus Calmette-Guérin (or Bacille Calmette-Guérin, BCG) is a vaccine against Tuberculosis that is prepared from a strain of the attenuated ^[32]

Vaccine

In November 2006, it was announced that a vaccine had been developed and tested with very promising results. Events in November All Saints' Day (formerly All Hallows Day a Christian holy day is celebrated on November 1, the day after Halloween Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. A vaccine is a biological preparation which is used to establish or improve immunity to a particular disease ^[33] The new vaccine, called TroVax, works in a totally different way to existing treatments by harnessing the patient's own immune system to fight the disease. TroVax is a Cancer vaccine being developed by Oxford BioMedica. Experts say this suggests that gene therapy vaccines could prove an effective treatment for a whole range of cancers. Gene therapy is the insertion of Genes into an individual's cells and tissues to treat a Disease, and Hereditary diseases in which a Oxford BioMedica is a British spin-out from Oxford University specialising in the development of gene-based treatments. The University of Oxford (informally "Oxford University" or simply "Oxford" located in the city of Oxford, Oxfordshire, England is the Phase III trials are underway for renal cancers and planned for colon cancers. ^[34]

Treatment of liver metastases

According to the American Cancer Society statistics in 2006,[3] over 20% of patients present with metastatic (stage IV) colorectal cancer at the time of diagnosis, and up to 25% of this group will have isolated liver metastasis that is potentially resectable. Lesions which undergo curative resection have demonstrated 5-year survival outcomes now exceeding 50%. ^[35]

Resectability of a liver metastasis is determined using preoperative imaging studies (CT or MRI), intraoperative ultrasound, and by direct palpation and visualization during resection. Lesions confined to the right lobe are amenable to en bloc removal with a right hepatectomy (liver resection) surgery. Smaller lesions of the central or left liver lobe may sometimes be resected in anatomic "segments", while large lesions of left hepatic lobe are resected by a procedure called hepatic trisegmentectomy. Treatment of lesions by smaller, non-anatomic "wedge" resections is associated with higher recurrence rates. Some lesions which are not initially amenable to surgical resection may become candidates if they have significant responses to preoperative chemotherapy or immunotherapy regimens. Lesions which are not amenable to surgical resection for cure can be treated with modalities including radio-frequency ablation (RFA), cryoablation, and chemoembolization.

Patients with colon cancer and metastatic disease to the liver may be treated in either a single surgery or in staged surgeries (with the colon tumor traditionally removed first) depending upon the fitness of the patient for prolonged surgery, the difficulty expected with the procedure with either the colon or liver resection, and the comfort of the surgery performing potentially complex hepatic surgery.

Poor pronostic factors of patients with liver metastasis include:

• Synchronous (diagnosed simultaneously) liver and primary colorectal tumors
• A short time between detecting the primary cancer and subsequent development of liver mets
• Multiple metastatic lesions
• High blood levels of the tumor marker, carcino-embryonic antigen (CEA), in the patient prior to resection
• Larger size metastatic lesions

Support therapies

Cancer diagnosis very often results in an enormous change in the patient's psychological wellbeing. Various support resources are available from hospitals and other agencies which provide counseling, social service support, cancer support groups, and other services. Cancer support groups provide a setting in which Cancer patients can talk about living with cancer with others who may be having similar experiences These services help to mitigate some of the difficulties of integrating a patient's medical complications into other parts of their life.

Prognosis

Survival is directly related to detection and the type of cancer involved. Survival rates for early stage detection is about 5 times that of late stage cancers. CEA level is also directly related to the prognosis of disease, since its level correlates with the bulk of tumor tissue.

Follow-up

The aims of follow-up are to diagnose in the earliest possible stage any metastasis or tumors that develop later but did not originate from the original cancer (metachronous lesions).

The U. S. National Comprehensive Cancer Network and American Society of Clinical Oncology provide guidelines for the follow-up of colon cancer. National Comprehensive Cancer Network (NCCN is an alliance of twenty-one cancer centers most of which are designated by the National Cancer Institute (of the National About ASCO The American Society of Clinical Oncology ( ASCO) is the world's leading Professional organization representing Physicians ^[36][37] A medical history and physical examination are recommended every 3 to 6 months for 2 years, then every 6 months for 5 years. The medical history or Anamnesis of a Patient is information gained by a Physician or other healthcare professional by asking specific questions Physical examination or clinical examination is the process by which a Health care provider investigates the body of a Patient for signs Carcinoembryonic antigen blood level measurements follow the same timing, but are only advised for patients with T2 or greater lesions who are candidates for intervention. Carcinoembryonic antigen (CEA is a Glycoprotein involved in Cell adhesion. A CT-scan of the chest, abdomen and pelvis can be considered annually for the first 3 years for patients who are at high risk of recurrence (for example, patients who had poorly differentiated tumors or venous or lymphatic invasion) and are candidates for curative surgery (with the aim to cure). Computed tomography (CT is a Medical imaging method employing Tomography. A colonoscopy can be done after 1 year, except if it could not be done during the initial staging because of an obstructing mass, in which case it should be performed after 3 to 6 months. Colonoscopy is the endoscopic examination of the large colon and the distal part of the small bowel with a CCD camera or a Fiber optic If a villous polyp, polyp >1 centimeter or high grade dysplasia is found, it can be repeated after 3 years, then every 5 years. For other abnormalities, the colonoscopy can be repeated after 1 year.

Routine PET or ultrasound scanning, chest X-rays, complete blood count or liver function tests are not recommended. Positron emission tomography ( PET) is a Nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the A chest X-ray, commonly abbreviated CXR, is a projection radiograph ( X-ray) taken by a Radiographer, of the Thorax which is used A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is Liver function tests (LFTs or LFs which include liver enzymes, are groups of Clinical biochemistry laboratory blood assays designed to give information about the ^[36][37] These guidelines are based on recent meta-analyses showing that intensive surveillance and close follow-up can reduce the 5-year mortality rate from 37% to 30%. ^[38][39][40]

Prevention

Most colorectal cancers should be preventable, through increased surveillance, improved lifestyle, and, probably, the use of dietary chemopreventative agents.

Surveillance

Most colorectal cancer arise from adenomatous polyps. These lesions can be detected and removed during colonoscopy. Studies show this procedure would decrease by > 80% the risk of cancer death, provided it is started by the age of 50, and repeated every 5 or 10 years. ^[41]

As per current guidelines under National Comprehensive Cancer Network, in average risk individuals with negative family history of colon cancer and personal history negative for adenomas or Inflammatory Bowel diseases, flexible sigmoidoscopy every 5 years with fecal occult blood testing annually or double contrast barium enema are other options acceptable for screening rather than colonoscopy every 10 years (which is currently the Gold-Standard of care). National Comprehensive Cancer Network (NCCN is an alliance of twenty-one cancer centers most of which are designated by the National Cancer Institute (of the National An adenoma is a collection of growths (-oma of glandular origin In Medicine, inflammatory bowel disease ( IBD) is a group of inflammatory conditions of the large intestine and Small intestine

Lifestyle & Nutrition

The comparison of colorectal cancer incidence in various countries strongly suggests that sedentarity, overeating (i. e. , high caloric intake), and perhaps a diet high in meat (red or processed) could increase the risk of colorectal cancer. In contrast, a healthy body weight, physical fitness, and good nutrition decreases cancer risk in general. Accordingly, lifestyle changes could decrease the risk of colorectal cancer as much as 60-80%. ^[42]

A high intake of dietary fiber (from eating fruits, vegetables, cereals, and other high fiber food products) has, until recently, been thought to reduce the risk of colorectal cancer and adenoma. In the largest study ever to examine this theory (88,757 subjects tracked over 16 years), it has been found that a fiber rich diet does not reduce the risk of colon cancer. ^[43] A 2005 meta-analysis study further supports these findings. ^[44]

The Harvard School of Public Health states: "Health Effects of Eating Fiber: Long heralded as part of a healthy diet, fiber appears to reduce the risk of developing various conditions, including heart disease, diabetes, diverticular disease, and constipation. Despite what many people may think, however, fiber probably has little, if any effect on colon cancer risk. " ^[45]

Chemoprevention

More than 200 agents, including the above cited phytochemicals, and other food components like calcium or folic acid (a B vitamin), and NSAIDs like aspirin, are able to decrease carcinogenesis in pre-clinical development models: Some studies show full inhibition of carcinogen-induced tumours in the colon of rats. Non-steroidal anti-inflammatory drugs, usually abbreviated to NSAID s or NAID s, are drugs with Analgesic, Antipyretic and in higher Pre-clinical development is a stage of research that begins before Clinical trials (testing in humans can begin and during which important feasibility iterative testing and Other studies show strong inhibition of spontaneous intestinal polyps in mutated mice (Min mice). Chemoprevention clinical trials in human volunteers have shown smaller prevention, but few intervention studies have been completed today. Calcium, aspirin and celecoxib supplements, given for 3 to 5 years after the removal of a polyp, decreased the recurrence of polyps in volunteers (by 15-40%). The "chemoprevention database" shows the results of all published scientific studies of chemopreventive agents, in people and in animals. ^[46]

Aspirin chemoprophylaxis

Aspirin should not be taken routinely to prevent colorectal cancer, even in people with a family history of the disease, because the risk of bleeding and kidney failure from high dose aspirin (300mg or more) outweigh the possible benefits. ^[47]

A clinical practice guideline by the U.S. Preventive Services Task Force (USPSTF) recommended against taking aspirin (grade D recommendation). A medical guideline (also called a clinical guideline, clinical protocol or clinical practice guideline) is a document with the aim of guiding decisions Aspirin, or acetylsalicylic acid (ASA (əˌsɛtɨlsælɨˌsɪlɨk ˈæsɨd is a Salicylate drug, often used as an Analgesic to relieve ^[48] The Task Force acknowledged that aspirin may reduce the incidence of colorectal cancer, but "concluded that harms outweigh the benefits of aspirin and NSAID use for the prevention of colorectal cancer". A subsequent meta-analysis concluded "300 mg or more of aspirin a day for about 5 years is effective in primary prevention of colorectal cancer in randomised controlled trials, with a latency of about 10 years". In Statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses ^[49] However, long-term doses over 81 mg per day may increase bleeding events. ^[50]

Calcium

A meta-analysis by the Cochrane Collaboration of randomized controlled trials published through 2002 concluded "Although the evidence from two RCTs suggests that calcium supplementation might contribute to a moderate degree to the prevention of colorectal adenomatous polyps, this does not constitute sufficient evidence to recommend the general use of calcium supplements to prevent colorectal cancer. In Statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses The Cochrane Collaboration is a group of over 11500 volunteers in more than 90 countries who apply a rigorous systematic process to review the effects of interventions tested in biomedical A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare ". ^[51] Subsequently, one randomized controlled trial by the Women's Health Initiative (WHI) reported negative results. A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare ^[52] A second randomized controlled trial reported reduction in all cancers, but had insufficient colorectal cancers for analysis. A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare ^[53]

Mathematical modeling

Colorectal cancer has been for years subject of mathematical modeling. ^[54] For a comprehensive overview of current computational approaches on colorectal cancer see the Integrative Biology web page.

Famous people diagnosed with colorectal cancer

• Ruth Bader Ginsburg
• Tammy Faye Messner died July 20, 2007
• Audrey Hepburn [4]
• Harold Wilson [5]
• Pope John Paul II [6]
• Ronald Reagan [7]
• Elizabeth Montgomery, American Actress (died at age 62; died 8 weeks after being diagnosed with colon cancer. Ruth Joan Bader Ginsburg (born March 15 1933 Brooklyn New York) is an Associate Justice on the U Tamara "Tammy" Faye Messner ( March 7, 1942 – July 20, 2007) was an American Christian singer, evangelist Audrey Hepburn ( &ndash) was an English/Dutch Academy Award - Emmy Award - Tony Award - and Grammy Award -winning film and stage actress James Harold Wilson Baron Wilson of Rievaulx, KG, OBE, FRS, PC (11 March 1916 &ndash 24 May 1995 was one of the most prominent British politicians Pope Elizabeth Victoria Montgomery ( April 15, 1933 &ndash May 18, 1995) was an American Film and television see [8])
• Charles Schulz, Creator of Peanuts (died at age 77; died 60 days after being diagnosed with colon cancer) [9]. Charles Monroe Schulz (November 26 1922 &ndash February 12 2000 was an American Cartoonist best known worldwide for his Peanuts Comic strip Peanuts is a syndicated daily and Sunday Comic strip written and illustrated by Charles M
• Lillian Board, British athlete
• Malcolm Marshall, Legendary West Indian and Hampshire Cricketer [10]
• Achille-Claude Debussy, Famous French composer [11]
• Bobby Moore, 1966 England World cup winning captain (died at age 51; died 2 years after being diagnosed with colon cancer) [12]
• Babe Didrikson Zaharias, Legendary American athlete [13]
• Joel Siegel, movie critic and Host of Good Morning America (died between ages 63-65; died 10 years after being diagnosed with colon cancer)
• Eric Turner, second player taken in the 1991 NFL Draft
• Walter Matthau died from metastatic colon cancer on July 1, 2000
• Vince Lombardi, legendary coach of the Green Bay Packers, died of metastatic colon cancer
• Rod Roddy, previous announcer for The Price Is Right (died at age 66; died 2 years after being diagnosed with colon cancer)
• George David Low, American aerospace executive and a former NASA astronaut; died 2008
• Corazon Aquino, Former president of the Philippines. Lillian Barbara Board MBE ( December 13, 1948 &ndash December 26, 1970) was an athlete from Great Malcolm Denzil Marshall ( April 18, 1958 - November 4, 1999) was a West Indian Cricketer Primarily a Fast bowler Achille-Claude Debussy (aʃil klod dəbysi (August 22 1862 &ndash March 25 1918 was a French Composer. Robert Frederick Chelsea "Bobby" Moore, OBE (12 April 1941 - 24 February 1993 was an English footballer. Mildred Ella ("Babe" Didrikson Zaharias ( June 26, 1911 &ndash September 27, 1956) was an American athlete named Joel Siegel ( July 7, 1943 – June 29, 2007) was an American Film critic for the ABC morning news show Good Morning America ( GMA) is a morning news show that is broadcast on the ABC television network debuting on November Eric Ray Turner ( September 20, 1968 &mdash May 28, 2000) was a Defensive back who played for the Cleveland Browns, the The 1991 National Football League Annual Player Selection Meeting took place April 21 and April 22 1991 at the Marriott Marquis Hotel in Walter John Matthau ( October 1, 1920 – July 1, 2000) was an American award-winning Actor best known for his role Vincent Thomas Lombardi ( June 11, 1913 &ndash September 3, 1970) was an American football coach Robert Ray "Rod" Roddy ( September 28, 1937 &ndash October 27, 2003) was an American radio and television Announcer The Price Is Right is an five time Emmy Award-winning American Game show centering on contestants guessing the retail prices of featured prizes George David Low ( February 19 1956 – March 15, 2008 Education Low graduated from Langley High School, McLean The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program María Corazón Cojuangco-Aquino (born María Corazón Sumulong Cojuangco on January 25, 1933) widely known as Cory Aquino, was the 11th The President of the Philippines is the head of state and government of the Republic of the Philippines. The Philippines ( Filipino: Pilipinas, officially known as the Republic of the Philippines (fil ''Republika ng Pilipinas'' RP [14]

References

See also

• Hereditary nonpolyposis colorectal cancer
• Diet and cancer
• Bowel & Cancer Research

External links

• Bowel & Cancer Research UK
• Colon Cancer Alliance
• Colorectal Cancer Coalition
• National Cancer Institute (Cancer.gov) colorectal cancer
• Current clinical trials
• europacolon Pan European Not for Profit dedicated to colorectal cancer
• Complementary medical clinical trials
• Photos at: Atlas of Pathology
• Bowel Cancer UK (charity)
• Tackle Colon Cancer
• Cancer.Net: Colorectal Cancer
• Beating Bowel Cancer (UK charity)
• Colorectal cancer screening - the World Gastroenterology Organisation (WGO)