COLARIS^® Case E

The patient was diagnosed with colon cancer at age 43 and pancreatic cancer at age 54. Her family history of cancer consists of multiple family members with HNPCC-associated cancers, often at early ages. This patient pursued Comprehensive COLARIS^® and Reflex MSH6 Analysis due to her suggestive personal and family history of HNPCC-associated cancers. The Myriad Mutation Prevalence Table estimated a 23% chance for this patient to test positive for an MLH1 or MSH2 mutation. However, no mutation was detected by genetic testing.

Genetic Evaluation

• This patient's family history is highly suggestive of HNPCC. The no mutation detected result for Comprehensive COLARIS^® and Reflex MSH6 Analysis does not rule out hereditary risk in this family.

• Although the majority of mutations in MLH1, MSH2 or MSH6 are detected by Comprehensive COLARIS^® and MSH6 Analysis, some less common mutations in these genes are not. It is also possible that this patient carries a mutation in another less common HNPCC gene (i.e. PMS2) or an as yet undiscovered gene for HNPCC.

• Tumor tissue analysis [i.e. microsatellite instability testing (MSI) or immunohistochemistry testing (IHC)] might be appropriate to screen for rarer causes of HNPCC. Please note that MSI and IHC are not diagnostic for HNPCC but they may help to direct medical management and further genetic testing.

• Due to the significant cancer risk in this family, it may be appropriate to investigate further testing for the other known HNPCC genes. These genes are not currently tested for at Myriad Genetic Laboratories. For information on clinical laboratories that perform this testing, contact Myriad's Medical Services Department at 1-800-469-7423 or the Regional Medical Specialist in your area.

• Further evaluation by a genetics specialist might be appropriate.

• Despite the no mutation detected results, this family must be managed for HNPCC.

Medical Management

For patient:

• Medical management should be the same as an individual who has an HNPCC mutation, since this patient's history is clinically diagnostic for HNPCC. Click here for the appropriate medical management for this patient. The patient's risk of developing 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 HNPCC.

• 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 HNPCC in whom no mutation is found through Comprehensive COLARIS^® or MSH6 Analysis.

• 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.

« Back to the list of cases
« Back to the main COLARIS^® Results page

© 2004-06, Myriad Genetic Laboratories, Inc.