Thinking about cancer or dealing with cancer risk can be scary or overwhelming, but we believe that receiving information and resources is comforting, empowering, and lifesaving.
A negative genetic test result can have several different meanings depending on the individual and family circumstances of the person tested.
In a family where a genetic mutation has already been identified, a negative test may be considered a "true negative." This means that the person does not have a higher risk for cancer than the general population. In a family with a known mutation, screening recommendations are different for someone who tests negative for the known mutation than for someone who tests positive. However, since cancer is a common disease and since most cancer has no known cause, a negative genetic test does not guarantee that a person won’t develop cancer in his or her lifetime.
Improvements in Testing Technology
In the past, some tests failed to identify certain BRCA1 and BRCA2 mutations known as 'rearrangements' as well as other mutations. Some families that previously tested as "uninformative negative" for BRCA in the past may benefit from expanded panels that look for newly identified BRCA mutations. The "BART" (BracAnalysis Rearrangement Test) is a panel that looks for specific rare genetic mutations known as "large rearrangements." BART testing is usually recommended in families that have a suspicious history of cancer but no identified mutation on comprehensive BRCA testing. Families from certain ethnicities including Latin America, Caribbean, and Near and Middle Eastern background are more likely to test positive for a BART mutation.
Multigene Panel Tests
Sometimes hereditary breast and ovarian cancers can be caused by changes in genes other than BRCA1 or BRCA2. Mutations in other genes will not show up in older tests that looked only for mutations in BRCA1 and BRCA2. Members of families with no known BRCA mutation but many cases of cancer in the family may still be at high-risk for cancer and may want to consider panel testing. They may also qualify to participate in research looking for other genes that might be linked to hereditary cancers. For more information please visit our page on participating in research.
A specialist in cancer genetics can interpret a negative test result and help you determine whether another genetic test may be appropriate for a your family. For more information visit our page on other hereditary cancer syndromes.