COLARIS AP^® CASE E

The patient is a woman diagnosed with approximately 20 colon adenomas at age 49. She has a very significant family history of colon cancer and adenomas, as well as other cancers associated with FAP. This patient pursued Comprehensive COLARIS AP^® due to her suggestive personal and family history. However, no mutation was detected by genetic testing.

Genetic Evaluation

• This patient's personal and family history is highly suggestive of an adenomatous polyposis syndrome, most likely AFAP due to the autosomal dominant appearance of the family history. The no mutation detected result for Comprehensive COLARIS AP^® does not rule out hereditary risk in this family.
• Although the majority of mutations in APC and MYH are detected by Comprehensive COLARIS AP^®, some less common mutations in these genes are not.
• Since there are reports of biallelic MYH mutations in patients who appear to have AFAP, further analysis of the MYH gene might be appropriate, especially if the patient is not of European ancestry.
• Further evaluation by a genetics specialist might be appropriate.
• Despite the "no mutation detected" results, this family must be managed for AFAP.

Medical Management

For patient:

• Medical management should be the same as an individual who has a mutation in APC, since this patient's history is clinically diagnostic for AFAP. Click here for the appropriate medical management for this patient. The patient's risk of developing additional adenomas and a second primary cancer is significantly increased.

With regard to at-risk relatives:

• Click here for the appropriate medical management for at-risk relatives. All at-risk relatives in this family should be treated as if they may have AFAP.
• Genetic testing would not be useful for unaffected relatives, since no mutation was detected in the patient with cancer.

Additional Steps

• Participation in research studies looking for additional gene mutations may be an option for families with AFAP in whom no mutation is found through Comprehensive COLARIS AP^®.
• Patients also have the option to bank a sample of DNA for use in the future, should additional genetic tests become available that may explain the family history, and the patient is no longer living. Genetic testing is always most useful when first performed on an affected member of the family.
• If you would like more information about possible research studies for a patient or DNA banking, please call your Regional Medical Specialist or 1-800-469-7423 to speak with a Myriad Medical Services Representative.

References

1. American Cancer Society Guidelines on Screening and Surveillance for the Early Detection of Colorectal Adenomas and Cancer - Women and Men at Increased Risk or High Risk. Available at www.cancer.org. Accessed September 14, 2005.
2. NCCN Clinical Practice Guidelines in Oncology. Colon Cancer, v. 4.2005. Available at www.nccn.org. Accessed September 14, 2005.
3. Winawer S, Fletcher R, Rex D, et al. (2003) Colorectal cancer screening and surveillance: clinical guidelines and rationale - update based on new evidence. Gastroenterology 124:544-60.

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