Over 50% of women with negative genetic test and family history of breast cancer are high risk

Researchers have found that over half of women with a family history of breast cancer with an uninformative negative genetic test result are identified as high risk. Therefore a negative genetic test doesn't preclude cancer risk in women with a family history of breast cancer. The study has been published in the American Journal of Surgery.

The majority of women who undergo genetic testing due to a significant family history of breast cancer receive negative results yet the incidence of cancer is much higher.

The researchers conducted a study to calculate the lifetime risk of breast cancer in women who received an uninformative genetic test result and were undergoing genetic counseling. The researchers performed a retrospective chart review of mutation-negative women presenting to a cancer risk assessment clinic. The lifetime risks of breast cancer were calculated using Claus, Gail, and Tyrer-Cuzick risk assessment models. They used three widely used risk assessment models and calculated lifetime breast cancer risks of women who had undergone genetic testing and received a negative result. They found that over half of the women included in the study were considered to be high-risk for the development of breast cancer. Approximately half (51%) of the women were classified as high-risk by at least one risk assessment model. The Tyrer-Cuzick model identified the highest proportion (43.2%) of patients as high-risk. Four percent (n = 4) of the sample was considered high-risk by all three models.