Prenatal Testing Offers Window for Finding Mother’s Cancer Risk

Harmful variants in the BRCA1 gene significantly increase an individual's lifetime risk of developing breast, ovarian, and pancreatic cancers, yet most carriers are unaware of their status. Those who inherit a BRCA1 gene variant have various options to reduce their cancer risk, including enhanced screening and surgery. Unfortunately, most individuals discover their BRCA1 carrier status only after a cancer diagnosis. Identifying the optimal timing for genetic testing is a major challenge. Pregnancy and obstetrical care present a unique opportunity for screening and identifying patients before cancer development. Now, researchers investigating the inclusion of BRCA1 testing during obstetrical prenatal carrier screening have found this approach to be cost-effective and capable of identifying at-risk individuals at a critical time when preventative strategies could be lifesaving.

In the new study, a research team that included investigators from Weill Cornell Medicine (New York City, NY, USA) simulated the clinical outcomes for a hypothetical cohort of 1,429,074 pregnant patients in the U.S. who could undergo BRCA1 testing if it were included in prenatal carrier screening. This cohort size was based on data indicating that 39% of pregnant patients receive expanded carrier screening. The model began with patients at age 33, the median age for prenatal carrier screening in the U.S., and followed them until age 80. The primary outcome measured was the cost-effectiveness of BRCA1 testing during obstetrical prenatal carrier screening. Secondary outcomes included BRCA1 mutation positivity rates, cancer cases, cancer deaths, and direct medical costs.

The study found that incorporating BRCA1 testing identified an additional 3,716 BRCA1-positive patients, prevented 1,394 breast and ovarian cancer cases, and resulted in 1,084 fewer deaths. Compared to not testing for BRCA1, adding this test during prenatal carrier screening proved to be cost-effective, with an incremental cost-effectiveness ratio of USD 86,001 per quality-adjusted life year. While the study focused solely on BRCA1, researchers believe that including other hereditary cancer genes, such as BRCA2, RAD51C, RAD51D, BRIP1, and PALB2, during prenatal carrier screening could also be cost-effective. Presently, no obstetrical prenatal carrier screening panels include BRCA1 or other hereditary breast and ovarian cancer genes. Researchers are currently in discussions with genetic testing companies to integrate these genes into their products for pregnant women or those planning to become pregnant. They aim to initiate a prospective clinical trial to demonstrate feasibility and gather perspectives from both patients and providers on this screening process.

“It is a minimal increase in cost for the genetic testing companies to add on more genes,” said Dr. Shayan Dioun, assistant professor of obstetrics and gynecology at Columbia University Irving Medical Center. “I would expect that there would be an even bigger benefit if all these genes were integrated. We would be picking up people with other mutations and potentially prevent them from developing other cancers.” The results of the research team's study were publshed in the American Journal of Obstetrics and Gynecology on April 14, 2024.

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