As many people know, October is Breast Cancer Awareness month, which is a terrific opportunity to discuss screening for a familial breast cancer syndrome.
Traditionally, 5-10% of all cancers are hereditary, which means the vast majority of cancer patients have no family history of cancer at all. However, if cancer does run in one's family, being tested for certain genetic mutations can lead to increased cancer surveillance, risk-reducing surgeries, behavior modifications, and can alert other family members to risk. The mutations BRCA1 and BRCA2 are autosomal dominant germline mutations, meaning that they are handed down to offspring, and only one copy is sufficient to increase a person's chance of developing cancer. A woman with a BRCA1 or BRCA2 mutation has a 57-87% risk of developing breast cancer by age 70, and men with BRCA1 or BRCA2 mutations have a 1.2-6% lifetime risk of developing breast cancer. These mutations increase lifetime risk of other cancers as well, such as ovarian, pancreatic and prostate cancers. Anyone with a family member known to have a BRCA1 or BRCA2 mutation should seek testing, and optimally consult a genetic counselor. Genetic counselors assist physicians in assessing the need for genetic testing in patients who have a strong family history of various cancers. For example, according to the current guidelines published by the National Comprehensive Cancer Network (NCCN), testing for BRCA1 and BRCA2 should be performed in women with breast cancer who: are younger than 45 years old, who are younger than 50 and have at least one close family member with breast cancer, and in women younger than 60 with the triple-negative variant of breast cancer (to name a few). There are several additional criteria for genetic testing, for breast cancer genes and not all BRCA1 and BRCA2 mutant variants are pathogenic. Therefore, it is optimal, both for patients and for physicians, to involve genetic counselors when performing and assessing needs for genetic testing, to navigate the complexities of this important subject.
Authored by Ivy Altomare, MD
Associate Professor of Medicine
Division of Medical Oncology
Duke University Medical Center
Duke Cancer Network