Over Age 50, BRCA1 and BRCA2 Mutations Still Linked with Higher Cancer Risk

According to the American Cancer Society, a woman with a BRCA1 or BRCA2 gene mutation has up to a seven in 10 chance of developing breast cancer by the time she’s 80. While these mutations are often linked with onset at a younger age, a new study shows that the risk of cancer persists in older women.

Researchers from University of Toronto’s Lawrence S. Bloomberg Faculty of Nursing recently published the findings of a study following more than 2000 women between age 50 and 75 with a BRCA mutation, who had not yet been diagnosed with cancer. The team found that even after age 50, the risk of developing any type of cancer was 49% for a BRCA1 mutation and 43% for a BRCA2 mutation, with certain cancers most common.

Kelly Metcalfe, lead researcher and professor at the Lawrence S. Bloomberg Faculty of Nursing, says, “What is striking about our results is that breast and ovarian cancers were the most frequently observed cancers occurring and that is concerning, considering we know how to reduce the risk of cancer in women who have these genetic risk factors.”

There are surgeries that can be done to reduce the risk, and those who had not undergone them saw a higher disease prevalnce. In this study, 15% of participants had a preventative bilateral mastectomy and 43% had their ovaries and fallopian tubes removed before the age of 50. BRCA1 carriers who didn’t have these surgeries saw a 77% risk of developing cancer, and BRCA2 carriers had a 67% risk. Meanwhile, the women who had done so had just a 9% risk.

The team says one limitation of their study is that the women were from 16 different countries and some may have limited access to such surgeries where they live. There also wasn’t information on whether the participants had received genetic counseling.

Metcalf says, “We are not aware of whether the participants in our study received additional counseling about their elevated risk of cancer as they age and we are also unable to determine why some of these women chose to forgo preventative surgery before the age of 50. However, it is important to point out that screening alone only reduces mortality risk by increasing the chances of detecting the cancer early, it does not reduce the risk of cancer occurring.”

She says going forward, she hopes to investigate the reasons why women choose to or not to undergo preventative surgeries and how well they understand their risk.

You can read the whole study in the journal Cancer.