Research from Tufts Medical Center is offering a glimmer of hope to expecting mothers with undiagnosed cancer. A prenatal test for genetic disorders such as Down syndrome has been shown to detect cancer in the mother by returning false positives in the fetus for genetic abnormalities.
Published in Monday’s issue of JAMA, researchers at Tufts analyzed eight cases of test results that came back with false positives for genetic abnormalities in the fetus. Instead, the false readings were not caused by the DNA of the unborn child, but cancer DNA from the mother in the samples.
Jenny Bernstein, a study participant from San Francisco, explained how the situation played out for her and her unborn child.
“They said babies with the chromosomal issues they found in my sample typically don’t survive. I was freaking out. I didn’t know what was going on.”
Follow-up tests a week later showed the initial test was a false positive. It wasn’t until two months later that she was admitted to the emergency room with shoulder pain and breathing problems that Ms. Bernstein discovered she had non-Hodgkin’s lymphoma.
It was cancer that was the source of the abnormal genetic testing that initially showed the false positive for chromosomal abnormalities in her unborn child.
Dr. Diana Bianchi, executive director of the Mother Infant Research Institute at Tufts and lead researcher for this study called the results ‘very unexpected.’
“It’s important that women are aware of this possibility. It very strongly shows that women should not take any immediate action based on the screening test.”
Noninvasive Prenatal Testing
A relative new medical advancement, the test offers expecting mothers information about possible chromosomal abnormalities in the fetus. The test can be offered as early as ten weeks into a pregnancy, and analyzes fragments of both placenta and maternal DNA.
In this study, the samples also contained the mother’s cancer DNA in the plasma.
A cancer diagnosis in pregnant women has an incidence rate of about 1 in 1,000 women. Not rare, but also not common either. Most cancers detected center around the breast, cervix, colon and ovary.
In the case of Ms. Bernstein, non-Hodgkin’s lymphoma is a type of blood cancer. During the study, the women were tested multiple times, with some being tested both during and after the pregnancy.
A participant with colorectal cancer was tested after treatment, and the abnormality vanished, possibly showing the treatments effect.
What happens now? Dr. Bianchi is already pushing for more research for the prenatal test and its possible link to cancer screening in pregnant women.
“Noninvasive prenatal testing results may lead to findings of an underlying maternal condition, which, in these cases, was due to cancer. The take-home message is that women should be aware of this possibility when they seek testing. More research needs to be done to further study this occurrence to help guide physicians on how to counsel women and manage their follow-up care.”
It’s a remarkable study and hopefully will lead to more robust tests. What if researchers could devise a simple test that could seek out cancer DNA in all patients?