Testing for a Genetic Susceptibility to Cancer

Who should consider testing?
Generally only a person with a family history of a specific type of cancer or cancer syndrome. The person tested may or may not have had cancer. For example, a family history of breast or ovarian cancer may prompt BRCA testing, whereas a family history of colorectal cancer may lead to testing for hereditary nonpolyposis colorectal cancer or familial polyposis. There are currently about a dozen familial cancer susceptibility syndromes for which DNA testing is commercially available.

What is the procedure for testing?
Persons considering such testing should contact Peter T. Rowley, M.D., UR Cancer Center medical geneticist specializing in cancer susceptibility, or genetic counselor Starlene Loader, at (716) 275-0169.

A genetic evaluation and patient education should precede actual testing. At the first visit a complete family history of cancer is recorded, the appropriate type of test is identified, and the advantages and disadvantages of testing are explained. If the patient coming for consultation has not had cancer, generally the first family member to be tested should be one who has had the type of cancer in question. Otherwise a negative result on a family member who has not had cancer may be falsely reassuring. The patient is provided written material for review at home.
The patient who decides to proceed with testing returns for a second visit. At this time informed consent is given and blood drawn. When test results are available, the patient returns for an explanation and a discussion of the implications for surveillance and for other family members.

What are the advantages of genetic testing?
Individuals who have an inherited susceptibility often develop cancer at a younger age than others and therefore surveillance should start earlier than is customary. Some patients choose prophylactic surgery. Persons who have already had cancer may have an increased risk of a second cancer. Some persons are motivated to be tested in order to alert their family members, especially their children, to any increased risk, although children are not tested until they become adults. If a mutation has been documented in a relative who has had cancer, the absence of this mutation in a patient generally means that the patient's risk is not increased above the general public despite the positive family history.

What are the disadvantages of genetic testing?
Persons found to have a mutation may be anxious or depressed or disappointed about the interventions available. Hence, pretest education is important so that a candidate for testing understands the implications of the possible test results before choosing testing. A person detected to have a mutation could possibly experience discrimination by insurance companies or employers. When a person found to have a mutation informs a relative of their risk, the response is difficult to predict and sometimes negative .
A person who has not had cancer may be falsely reassured by a negative test result unless a mutation has first been demonstrated in an affected family member. Finally, a person may be found to have a DNA alteration in the gene not previously reported and hence of uncertain significance.

Who pays for genetic testing?
At the present time, DNA testing for a genetic susceptibility to cancer is expensive for the first family member tested. Once the mutation in the family has been identified, the cost of testing other family members is much lower.
Insurance companies are deciding about paying for these tests on a person-by-person basis. They are more likely to cover the cost if finding a mutation is likely and if it would alter patient management. Some patients choose to pay for testing themselves in order to keep their testing confidential.

How much genetic testing has been done in Rochester?
In a recent clinical trial of BRCA testing conducted by Rowley and Loader, members of 140 Rochester families came for pretest education and 87 proceeded to testing. Thirteen of these families were found to have a deleterious BRCA1 or BRCA2 mutation. These families are being followed to assess whether they benefited from testing.

Links to other Cancer sites:

1. Cancer Center at the University of Rochester Medical Center
2. Cornell University, Program on Breast Cancer and Envriomnental Risk Factors in New York State (BCERF)
3. Hereditary Colon Cancer Association
4. Sloan Kettering site on Cancer
5. Sloan Kettering site on Colorectal Cancer
6. The National Cancer Institue
7. University of Pennsylvannia Cancer Center

Comments/Suggestions to: Mary_True@urmc.rochester.edu