The information in this topic may have changed since it was written. This executive summary reviews the topics covered in this PDQ summary on the genetics of breast and gynecologic cancers. Factors suggestive of a genetic contribution to both breast cancer and gynecologic cancer include 1 an increased incidence of these cancers among individuals with a family history of these cancers; 2 multiple family members affected with these and other cancers; and 3 a pattern of cancers compatible with autosomal dominant inheritance.
Both males and females can inherit and transmit an autosomal dominant cancer predisposition gene. Additional factors coupled with family history can influence an individual's risk of developing cancer—such as reproductive history, contraceptive and hormone replacement use, radiation exposure early in life, alcohol consumption and smoking, and physical activity.
Breast and ovarian cancer are present in several autosomal dominant cancer syndromes, although they are most strongly associated with highly penetrant germline pathogenic variants in BRCA1 and BRCA2. Colorectal cancer and, to a lesser extent, ovarian cancer and stomach cancer is also associated with Lynch syndrome. Genome-wide searches are showing promise in identifying common, low-penetrance susceptibility alleles for many complex diseases, including breast and gynecologic cancers, but the clinical utility of these findings remains uncertain.
Breast cancer screening strategies, including breast magnetic resonance imaging and mammography, are commonly performed in carriers of BRCA pathogenic variants and in individuals at increased risk of breast cancer. Initiation of screening is generally recommended at earlier ages and at more frequent intervals in individuals with an increased risk due to genetics and family history than in the general population. There is evidence to demonstrate that these strategies have utility in early detection of cancer.
In contrast, there is currently no evidence to demonstrate that ovarian cancer screening using cancer antigen— testing and transvaginal ultrasound leads to early detection of cancer. Chemoprevention strategies for breast cancer and chemoprevention strategies for ovarian cancer have been examined in this population. For example, tamoxifen use has been shown to reduce the risk of contralateral breast cancer among carriers of BRCA1 and BRCA2 pathogenic variants after treatment for breast cancer, but there are limited data in the primary cancer prevention setting to suggest that it reduces the risk of breast cancer among healthy female carriers of BRCA2 pathogenic variants.
