DELRAY BEACH, FL – As a result of their age, women over the age of 65 years old, who are diagnosed with breast cancer, are usually not offered hereditary cancer genetic testing. Guidelines and recommendations from organizations, like the National Comprehensive Cancer Network are centered on the idea that this group of women has less than a 2.5% chance of having one pathogenic variant in a high-penetrance cancer risk gene. However, a recent study by the Mayo Clinic Cancer Center suggests that women with breast cancer over the age of 65, and all breast cancer patients, should be offered testing, not matter their age.

The study, published in the Journal of Clinical Oncology, found that 3.18% of women over the age of 65 diagnosed with breast cancer had pathogenic variants in a cancer predisposition gene, which is much higher than the 2.5% guideline threshold.¹ The greatest prevalence of variations was found in BRCA1/2, PALB2, and CHEK2. This study also observed other subsets of this group were higher than the threshold of 2.5%, including women diagnosed with ER-negative breast cancer, 3.42%, and triple-negative breast cancer, 3.01%.

The corresponding author and principal investigator, Dr. Fergus Couch, stated, “As the 2.5% frequency is often used to trigger genetic testing, these results suggest that all women with estrogen receptor-negative breast cancer – and perhaps all women with breast cancer, including those diagnosed over age 65 – should be offered hereditary breast cancer testing.”²

Women with their germline variation results may benefit from targeted treatments, therapies and prevention strategies associated with secondary breast and other cancers. Dr. Couch also implored that, “We were not sure what this study of the older breast cancer population would yield, but our results support broader testing, regardless of age or family history.”²