Risk of cancer remains high for women over 50 with genetic BRCA1 or BRCA2 mutation

Feb. 28, 2023
New study examines rates of cancer occurrence and whether women are opting for risk-reducing surgeries.

Although genetic mutations in BRCA1 or BRCA2 are associated with a younger onset of breast and ovarian cancer, women with these genetic mutations continue to face a high risk of cancer incidence after age 50, even if they have not been previously diagnosed with cancer. This is according to a new study led by Kelly Metcalfe, a professor at the Lawrence S. Bloomberg Faculty of Nursing.

The study published recently in the American Cancer Society Journal Cancer, followed over 2000 women between the ages of 50 to 75, from 16 countries, who were aware they had a BRCA mutation and had no previous diagnosis of cancer. The study found that the cumulative risk of these women developing any type of cancer after the age of 50 was 49 percent for those with a BRCA1 mutation and 43 per cent for those with a BRCA2 mutation. For those in the study cohort who had not undergone a cancer risk-reduction surgery, the risk was even greater at 77 per cent for those with a BRCA1 mutation and 67 per cent for those with a BRCA2 mutation.

Of the women included in the study only 15 percent underwent a preventative bilateral mastectomy, and 43 percent a bilateral salpingo‐oophorectomy (BSO) – removal of both ovaries and fallopian tubes – before the age of 50. The study found that these women had the lowest risk of any occurrence of cancer at just 9 per cent.

Understanding the limitations of screening is of particular importance for women with either a BRCA1 or BRCA2 mutation especially in assessing their risk of ovarian cancer, as no good screening method exists to detect the cancer early enough. Metcalfe’s study references the National Comprehensive Cancer Network (NCCN) guidelines where it is recommended that women with a BRCA1 mutation undergo a BSO between ages 35-40 and those with BRCA2 mutation between 40-45.

University of Toronto release on Newswise