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Unusual Cancers of Childhood Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Abdominal Cancers

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Genetic syndromes associated with colorectal cancer

About 20% to 30% of adult patients with colorectal cancer have a significant history of familial cancer; of these, about 5% have a well-defined genetic syndrome.[88] The incidence of these syndromes in children has not been well defined. In one review, 16% of patients younger than 40 years had a predisposing factor for the development of colorectal cancer.[89] A later study documented immunohistochemical evidence of mismatch repair deficiency in 31% of colorectal carcinoma samples in patients aged 30 years or younger.[90] The most common genetic syndromes associated with the development of colorectal cancer are shown in Tables 3 and 4.

Table 3. Common Genetic Syndromes Associated With Adenomatous Polyposis

SyndromeGeneGene FunctionHereditary Pattern
Attenuated familial adenomatous polyposisAPC(5' mutations),AXIN2Tumor suppressorDominant
Familial adenomatous polyposis (Gardner syndrome)APCTumor suppressorDominant
Lynch syndrome (hereditary nonpolyposis colorectal cancer)MSH2, MLH1, MSH6, PMS2, EPCAMRepair/stabilityDominant
Li-Fraumeni syndromeTP53(p53)Tumor suppressorDominant
MYH-associated polyposisMYH(MUTYH)Repair/stabilityRecessive
Turcot syndromeAPC Tumor suppressorDominant
MLH1Repair/stabilityDominant

Table 4. Common Genetic Syndromes Associated With Hamartomatous Polyps

SyndromeGeneGene FunctionHereditary Pattern
Cowden syndromePTEN Tumor suppressorDominant
Juvenile polyposis syndromeBMPR1A, SMAD4, ENGTumor suppressorDominant
Peutz-Jeghers syndromeSTK11Tumor suppressorDominant

Familial polyposis is inherited as a dominant trait, which confers a high degree of risk. Early diagnosis and surgical removal of the colon eliminates the risk of developing carcinomas of the large bowel.[91] Some colorectal carcinomas in young people, however, may be associated with a mutation of the adenomatous polyposis coli (APC) gene, which also is associated with an increased risk of brain tumors and hepatoblastoma.[92] The familial APC syndrome is caused by mutation of a gene on chromosome 5q, which normally suppresses proliferation of cells lining the intestine and later development of polyps.[93] A double-blind, placebo-controlled, randomized phase I trial in children aged 10 to 14 years with familial adenomatous polyposis (FAP) reported that celecoxib at a dose of 16 mg/kg/day is safe for administration for up to 3 months. At this dose, there was a significant decrease in the number of polyps detected on colonoscopy.[94][Level of evidence: 1iiDiv] The role of celecoxib in the management of FAP is not known.

Another tumor suppressor gene on chromosome 18 is associated with progression of polyps to malignant form. Multiple colon carcinomas have been associated with neurofibromatosis type I and several other rare syndromes.[95]

Clinical presentation

Presenting symptoms are nonspecific and include abdominal pain, weight loss, change in bowel habits, anemia, and bleeding; the median duration of symptoms was about 3 months in one series.[70,73,96] Changes in bowel habits may be associated with tumors of the rectum or lower colon. Tumors of the right colon may cause more subtle symptoms but are often associated with an abdominal mass, weight loss, decreased appetite, and blood in the stool. Any tumor that causes complete obstruction of the large bowel can cause bowel perforation and spread of the tumor cells within the abdominal cavity.

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WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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