Author Affiliations: Department of Medicine and Herbert Irving Comprehensive Cancer Center (Drs Grann and Parsons); Department of Epidemiology and Health Policy, Mailman School of Public Health (Dr Grann); and Institute for Cancer Genetics and Department of Pathology (Dr Parsons), Columbia University Medical Center, New York, New York.
In the second half of the 20th century, women with a family history of breast cancer were treated with bilateral mastectomies. Among 639 such women in 1 study, the median length of survival after surgery was 14 years. Using their sisters as control participants, there was a large survival difference between women who underwent bilateral mastectomies and those who did not.1 By the 1990s, after the identification of hereditary breast cancer genes BRCA1 and BRCA2, an understanding began to emerge about the elevated lifetime risks of ovarian and breast cancers for women carrying deleterious mutations of the BRCA1 or BRCA2 genes.2,3 The effects of these discoveries moved quickly and helped define the extent of genetic heterogeneity and the penetrance of the 17q and 13q tumor suppressor gene regions.
Grann VR, Parsons RE. Defining Variations in Survival of BRCA1 and BRCA2 Mutation Carriers. JAMA. 2011;306(14):1597-1598. doi:10.1001/jama.2011.1476