GENETIC TESTING FOR BREAST CANCER

TYPES

Genetic tests that could detect breast cancer:

• Sanger sequencing analyzes a single DNA fragment for the presence of the mutation.
• Gene expression profiling analyzes one entire gene for the presence of mutations.
• Panel tests or “next-generation gene sequencing,” looks at a set of genes for mutations all at once.

DIAGNOSIS

A test outcome can be positive, indicating that the patient carries a gene mutation.

A negative test result suggests that they do not have the specific known mutation of the gene. It does not, however, rule out the probability of other genes having mutations. It also does not rule out the likelihood that breast cancer can develop. The majority of breast cancer cases are not inherited.

The outcomes of genetic testing for breast cancer may also be unclear or ambiguous. An ambiguous test outcome indicates that the gene has been identified as having a mutation, although not clear, the mutation affects the risk of developing breast cancer.

Over time, a patient does not go from being negative to being positive for the actual gene mutations they have been screened for, or vice versa.

A patient should consult with a genetic specialist again after getting genetic test results to explain what the findings indicate. Some family members, such as siblings and children, will also be affected by the results; if anyone is positive for a gene mutation, their siblings and offspring will also have a 50% chance of testing positive. First, a meeting with a genetic specialist is recommended so that possible outcomes will be discussed.