In a study reported in JAMA Network Open, Guo et al found that the proportion of positive BRCA genetic test results markedly declined between 2008 and 2018 among women aged ≥ 65 years in the United States, with the trend likely reflecting what the investigators call a loosening of testing criteria over the years.
As stated by the investigators, “Genetic testing for BRCA1/2 pathogenic variants has been used for targeted, individualized cancer prevention and treatment. A positive BRCA test result indicates a higher risk for developing BRCA-related cancers. During the past decade, testing criteria have loosened. The impact of these loosened criteria on BRCA testing in older women has not previously been studied.”
Study Details
The cross-sectional study involved data on 5,533 women aged ≥ 65 years with BRCA test results from a large national electronic health record data set (10% random sample from Optum’s de-identified Integrated Claims-Clinical data set). Among all women, 34.1% and 8.2% had a family history of breast and ovarian cancer, respectively, and 39.0% and 6.6% had a personal history of breast and ovarian cancer, respectively. Overall, 4,595 (84.6%) were White, 268 were Black, and 94 were Hispanic. The largest percentage (34.6%) resided in the Midwest region (West = 25.4%; Northeast = 20.5%; South = 17.9%).
“The significantly decreasing rate of positive BRCA test results is evident among women 65 years of age or older, which may be partly explained by loosening of testing criteria during the evaluated time range. However, socioeconomic and regional disparities were identified and persisted in testing use.”— Guo et al
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Key Findings
Among all women, positive BRCA test results decreased from 85.7% (36 of 42) in 2008 to 55.6% (140 of 252) in 2018 (annual percentage change = −2.55, 95% confidence interval [CI] = −3.45 to −1.64).
Positive test results decreased from 83.3% (20 of 24) in 2008 to 61.6% (61 of 99) in 2018 among women with breast or ovarian cancer and from 87.5% (21 of 24) in 2008 to 48.4% (74 of 153) in 2018 among women without breast or ovarian cancer (annual percentage change = −3.17 vs −2.49; P = .29).
Among the 1,502 women without positive test results, 45 (3.0%) were Black and 708 (47.1%) resided in the Midwest. Among the 4,031 women with positive test results, 228 (5.7%) were Black and 1,207 (29.9%) resided in the Midwest.
Overall, rates of positive test results decreased among patients residing in the Midwest and the Northeast and increased among patients in the West.
On multivariate analysis, women with positive test results were more likely to be Black (adjusted odds ratio [OR] = 1.52, 95% CI = 1.04–2.22), live in the West (adjusted OR = 2.67, 95% CI = 1.63–4.39) or South (adjusted OR = 1.80, 95% CI = 1.14–2.86), live in areas with a low percentage of college graduates (adjusted OR = 1.54, 95% CI = 1.10–2.17), or not have a personal history of breast or ovarian cancer (adjusted OR = 1.30, 95% CI = 1.12–1.50).
The investigators concluded, “The significantly decreasing rate of positive BRCA test results is evident among women 65 years of age or older, which may be partly explained by loosening of testing criteria during the evaluated time range. However, socioeconomic and regional disparities were identified and persisted in testing use.”
Fangjian Guo, MD, PhD, of the Department of Obstetrics and Gynecology, The University of Texas Medical Branch at Galveston, is the corresponding author for the JAMA Network Open article.
Disclosure: The study was supported in part by the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
