A recent study published in the New England Journal of Medicine indicates that prenatal cell-free DNA (cfDNA) tests, commonly used to screen for fetal chromosomal disorders, can also identify previously undetected cancers in expecting mothers. The research highlights the potential for these tests to serve as an early warning system, prompting further investigation and potentially improving maternal health outcomes.
Unexpected Findings in Prenatal Screening
The study, conducted by researchers at the National Institutes of Health (NIH), involved cancer screening of 107 pregnant women who had abnormal results from prenatal cfDNA testing. The screening methods included whole-body magnetic resonance imaging (MRI), standard diagnostic tests, and cfDNA sequencing. A significant 48.6% (52 women) of the participants were diagnosed with cancer, revealing the test's potential to uncover hidden malignancies.
The detected cancers spanned a range of types, including lymphomas (31 women), as well as colorectal, breast, lung, kidney, bile duct, and pancreatic cancers. Notably, more than half (56%) of the women diagnosed were asymptomatic, and another quarter had symptoms initially attributed to their pregnancy, such as stomach pain misdiagnosed as acid reflux.
Diagnostic Effectiveness
Whole-body MRI scans proved to be the most effective method for detecting cancers in this population. In contrast, standard diagnostic techniques, including medical history and physical examinations, were found to be of limited use in identifying the cancers or their locations. This suggests that relying solely on traditional methods may lead to delayed diagnoses in pregnant women with underlying malignancies.
Clinical Implications and Recommendations
The findings underscore the importance of taking abnormal prenatal cfDNA test results seriously. According to Dr. Diana Bianchi, director of the National Institute of Child Health and Human Development and senior author of the study, women with such results and their healthcare providers should pursue additional testing due to the substantial risk of cancer. Researchers estimate that approximately 1 in 10,000 women undergoing cfDNA testing each year will receive an abnormal result that requires further evaluation.
The study also points to the need for additional research to validate cfDNA sequencing patterns that could indicate cancer in young, pregnant women without obvious clinical symptoms. Further investigation into the causes of abnormal cfDNA results, including factors such as fibroids, placental chromosome variations, and clonal hematopoiesis, is warranted.
Study Limitations
The researchers noted the need for additional studies to validate cfDNA sequencing patterns described by the investigators that could indicate cancer in this young, pregnant population without obvious clinical symptoms.
