A woman getting a mammogram. Women who have harmful mutations of the BRCA… (Rhoda Baer / National Cancer…)
Women who inherit gene mutations that increase their likelihood of getting breast cancer now face an added worry: They may be prone to developing the disease earlier in life than their mothers and aunts did.
The discovery, by a team at the University of Texas M.D. Anderson Cancer Center in Houston, was reported Monday in the journal Cancer.
Harmful mutations in the BRCA 1 and BRCA 2 genes dramatically increase a woman's chance of developing breast and/orovarian cancer, according to this fact sheet from the National Cancer Institute. About 60% of women with a harmful mutation in BRCA 1 or BRCA 2 will develop breast cancer sometime during their lives. In the general population, about 12%of women will. BRCA mutations are responsible for 5% to 10% of breast cancer diagnoses.
Because they are so much more likely than women in the general population to develop cancer, women with the harmful mutations often undergo additional screenings and other interventions to catch disease early. Some even choose to have their breasts and/or ovaries removed as a preventive measure.
Physicians at M.D. Anderson, including study first author Dr. Jennifer Litton, treat many women with BRCA gene mutations and began to notice that women with a harmful mutation of the BRCA genes seemed to be receive breast cancer diagnoses at earlier ages than their older relatives had. To see if the anecdotal evidence held up, they compared the medical records of 106 BRCA-positive women who had been treated for breast cancer at the center with older relatives who had also had the disease, noting age at diagnosis, location of the mutation and year of birth.
They found a median age of diagnosis of 48 in the older generation and 42 in the younger one.
The discovery may mean physicians need to bump up their efforts to discover cancers in younger women with BRCA mutations, the coauthors wrote. "Currently, BRCA-positive women are counseled to start screening by 25 years, or five to 10 years earlier than their youngest affected family member. However, our findings show that we may need to continue to follow these trends with future generations, and make changes accordingly in order to best advise and care for women at greatest risk," Litton said in a statement.