How prenatal testing in mothers could transform cancer detection
I’m very excited about the possibility of using DNA-based testing for the screening of early cancer. Now, I know that I’m getting ahead of myself here because the test we’re talking about— referred to as noninvasive prenatal testing (NIPT)— is one that I personally use every day for most of my pregnant patients.
It’s a simple blood test that we conduct on the mother when she is between 10 and 20 weeks of her pregnancy, and what it does is it identifies fetal DNA and it looks at profiles of chromosomal abnormalities such as trisomies 21, 18, 13, and in some cases it looks at the fetal sex chromosomes X or Y. The test has a 99.9 percent accuracy rate on determining whether the baby may or may not be affected with any of these chromosomal abnormalities such as Down syndrome. This simple test is really becoming quite the standard of care in many obstetrical practices.
But what scientists in Belgium have reported is that they have identified very atypical genetic information that was not linked to the fetus or the mother, but that possessed a signature for cancer abnormalities. And, indeed, when these patients with these new chromosomal signatures were identified, they were referred for workup and were found to have cancers such as ovarian cancer, follicular lymphoma and Hodgkin’s lymphoma. What’s more, the study authors published in the journal JAMA Oncology that, statistically, finding three women with cancer in their study group of more than 6,000 people was consistent with the general population— which translates to one in every 1,000 to 2,000 women between ages 20 and 40.
This is a very important finding because this could have a huge impact on the way we screen for certain cancers. Its potential is even more promising because it suggests we’d be able to establish patterns of oncological DNA signatures and identify them in the bloodstream using the technological sophistication we already have for identifying fetal cells.
Remember: Many of the cancers identified are often found when they are in late stages of development, which makes cure rates very limited. So I think that we are going to see a lot of new research in this area, and I hope that, indeed, this method pans out because it would signal another chapter in eradicating late-stage cancer.