COLARIS AP^® CASE D

The patient is a woman diagnosed with colon cancer and 3 adenomas at the age of 42. Her family history of cancer consists of her sister, who has had more than 10 adenomas removed throughout her lifetime. This patient pursued Comprehensive COLARIS AP^® due to her personal and family history of colon cancer. 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 MAP due to the autosomal recessive 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.
• 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.

Medical Management

For patient:

• Colonoscopy is recommended within one year following the colon cancer diagnosis. The frequency of follow-up examinations will depend on the number of adenomas identified. If this initial exam is normal, colonoscopy should be repeated in three years and, if normal, repeated every five years.
• Consideration should be given to follow this patient as if she has AFAP or MAP based on her suggestive personal and family history. Click here for the appropriate medical management for APC and MYH mutation carriers.

With regard to at-risk relatives:

• Colonoscopic screening should begin by age 40 years or 10 years prior to the earliest diagnosis of colon cancer/adenomatous polyps in the family, whichever is earlier. Since this example illustrates a patient with colon cancer at age 42 years, this would mean colon cancer screening should begin at age 32 years in this family (e.g., for this patient's children).
• Unfortunately, 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 a suspected adenomatous polyposis syndrome 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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