(HealthDay News) — In a cohort of unselected postmenopausal women with breast cancer, 3.55 percent have pathogenic variants (PVs) in breast cancer-associated genes compared with 1.29 percent in cancer-free controls, according to a research letter published in the March 10 issue of the Journal of the American Medical Association.
Allison W. Kurian, M.D., from Stanford University in California, and colleagues examined the prevalence of PVs among women diagnosed with breast cancer after menopause versus the prevalence among cancer-free postmenopausal women. Data were included for women from the Women’s Health Initiative who were diagnosed with invasive breast cancer (2,195 women) or remained cancer-free (2,322 women) as of Sept. 20, 2017.
The researchers detected PVs in 6.74 percent (95 percent confidence interval [CI], 5.73 to 7.87 percent) of case participants and 4.01 percent (95 percent CI, 3.24 to 4.88) of control participants. A PV was detected in any breast cancer-associated gene in 3.55 percent (95 percent CI, 2.82 to 4.42 percent) and 1.29 percent (95 percent CI, 0.87 to 1.84 percent) of case and control participants, respectively. Of the women with BRCA1/2 PVs, 30.8 and 20 percent of case and control participants, respectively, met testing guidelines; of the participants with PVs in other breast cancer-associated genes, 34 and 16 percent of case and control participants, respectively, met testing guidelines. For PV prevalence in BRCA1/2 or other breast cancer-associated genes, there was no significant trend by age.
“Among postmenopausal patients with breast cancer, PV prevalence may be high enough to warrant testing even in the absence of early diagnosis age or family history,” the authors write.
Several authors disclosed financial ties to biotechnology companies, including Myriad Genetics, which partially funded the study.