RATIONALE: Identifying family and individual characteristics may help plan education and counseling for patients who are considering genetic testing.

PURPOSE: This clinical trial is studying education and counseling to see what effect they have in patients who are undergoing genetic testing for hereditary nonpolyposis colon cancer (recruitment of new families with HNPCC stopped as of 04-26-06, recruitment of persons within families already participating continues).

OBJECTIVES:

• Identify family characteristics, personality traits, and religious and spiritual beliefs that significantly affect individual decisions regarding mutation testing for hereditary nonpolyposis colon cancer (HNPCC) (recruitment of new families with HNPCC stopped as of 04-26-06, recruitment of persons within families already participating continues).
• Determine the impact of negative vs positive mutation test results on family relationships and psychological status.
• Assess expectations regarding testing and how they influence perceptions of risks and responses to risk notification.
• Determine the impact of risk notification on the frequency of screening/prevention activities.
• Formulate a standard diagnostic algorithm for determining microsatellite instability based on the analysis of tumors with this extensive array of markers and correlate specific replication error phenotypes with germline genotype.

OUTLINE: Participants complete a baseline assessment of knowledge, risk perception, and personality traits followed by a structured pretest education session. Participants are then offered the choice of whether or not to undergo genetic testing for mutations in hereditary nonpolyposis colon cancer (HNPCC) genes. Participants who choose to undergo genetic testing provide a blood sample for this purpose. Participants who undergo genetic testing receive results and counseling (recruitment of new families with HNPCC stopped as of 04-26-06, recruitment of persons within families already participating continues).

Available surveillance options are discussed for all participants. Psychological and behavioral outcomes are reassessed at 6 and 12 months for both those choosing and not choosing genetic testing.

Tumors (when available) are analyzed for mismatched repair deficiency on the basis of microsatellite instability.

PROJECTED ACCRUAL: A total of 900 participants will be accrued for this study, with a specific target of 200 individuals who have not experienced cancer within families identified with hereditary nonpolyposis colon cancer (HNPCC) mutations (recruitment of new families with HNPCC stopped as of 04-26-06, recruitment of persons within families already participating continues).

DISEASE CHARACTERISTICS:

• Meets one of the following criteria:

  • Family history consistent with hereditary nonpolyposis colon cancer (HNPCC)*

    • At least 3 relatives with histologically proven colorectal cancer or HNPCC-associated cancer and 1 is a first-degree relative of the other 2
    • At least 2 successive generations affected
    • Colorectal cancer (or HNPCC-associated cancer) diagnosed under age 50 in 1 of the relatives

  • Diagnosis of colorectal cancer under age 41

  • HNPCC-associated cancer/polyps* under age 41 with a microsatellite instability (MSI) phenotype

  • Multiple primary HNPCC-associated cancers* regardless of family history

  • Colorectal or other HNPCC-associated tumor/polyp* demonstrating a positive MSI phenotype and at least 1 second-degree (or closer) and 1 third-degree (or closer) relative with a HNPCC-associated cancer

    • 1 affected family member must have one of the following:

      • Right-sided colon cancer
      • Multiple primary HNPCC-associated cancers
      • Diagnosis of cancer prior to age 51 NOTE: *Recruitment of new families with HNPCC stopped as of 04-26-06, recruitment of persons within families already participating continues

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Not specified

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Not specified

Endocrine:

• Not specified

Radiotherapy:

• Not specified

Surgery:

• Not specified