Women with both breast and uterine cancer are more likely to carry genetic mutations than women with either breast or uterine cancer alone, according to results of a retrospective analysis of test results.
The majority of the mutations identified were actionable, suggesting that women with breast and uterine cancer should be offered expanded genetic testing, authors of the analysis wrote in.
“Expanded testing for patients with breast and uterine cancer can help guide management by identifying more patients who may benefit from additional surveillance, along with at-risk family members,” said Kelly Fulk, an oncology genetic specialist at Ambry Genetics, and her coauthors.
The analysis by Ms. Fulk and her colleagues at St. Thomas Health, Nashville, and the University of California, Irvine, was based on a cohort of 52,000 women who had undergone multigene panel testing.
That cohort included 1,650 women with both breast and uterine cancer, of whom about 70% were white, and more than 94% were older than age 50 years at the time of testing. Their median age at first diagnosis was 56 years for breast cancer and 58 years for uterine cancer.
A total of 231 women with breast and uterine cancer, or 14.0%, carried at least one pathogenic mutation or likely pathogenic variant, Ms. Fulk and her colleagues reported. By comparison, mutations were seen in 9.3% of women with breast cancer only (P less than .001), 11.5% of women with uterine cancer only (P = 4.63 x 10–3), and 6.8% of women with no personal cancer history (P less than .001).
Women with both breast and uterine cancer more often had mutations in ATM, BARD1, BRCA2, MSH2, MSH6, PALB2, PMS2, and PTEN, when compared with those women with no personal cancer history, according to the report by Ms. Fulk and her coauthors.
When compared with women with just breast cancer, the women with both breast and uterine cancer more often had mutations in BRCA1, MLH1, MSH2, MSH6, PMS2 and PTEN, they added, noting that women with both cancers were twice as likely to have a BRCA1 mutation (odds ratio, 2.01; 95% confidence interval, 1.08-3.39, P = .016).
While this study had limitations, including its retrospective nature and use of genetic tests with varying numbers of genes analyzed, authors said the results nonetheless support expanded testing in women with both breast and uterine cancers to help guide therapy and cancer surveillance.
“Mutations associated with hereditary breast and ovarian cancer, Lynch syndrome, Cowden syndrome, and Li-Fraumeni syndrome have clear guidelines regarding management and surveillance for other cancers, which can benefit patients and their at-risk family members,” the investigators said.
Ms. Fulk and five coauthors reported that they are paid employees of Ambry Genetics. No other disclosures were provided.
SOURCE: Fulk K et al. Gynecol Oncol. 2019 Jan 3. .