Genetic Study of Familial Factors in Patients With Colon Cancer

DISEASE CHARACTERISTICS:

• Diagnosis of colon cancer or polyps at age 70 or under
• Has a living full sibling with diagnosis of colon cancer or polyps at age 70 or under
• No history of familial adenomatous polyposis syndrome
• No hereditary nonpolyposis colon cancer, according to Amsterdam criteria
• No known I1370K adenomatous polyposis of the colon susceptibility variant

• Enrolled on 1 of the following clinical trials:

  • CLB-9581
  • CLB-89803
  • CLB-80001 NOTE: Patients do not need to be receiving protocol therapy. Patients who are outside the treatment protocol's follow-up range are eligible. Patients who discontinued therapy for any reason, including toxic effects, are eligible.

PATIENT CHARACTERISTICS:

Age

• 70 and under at diagnosis

Other

• No significant psychiatric illness that would preclude giving informed consent
• No inflammatory bowel disease (in patient or sibling)