A new study has revealed that genetic testing created to detect chromosomal abnormalities in fetuses could also detect underlying conditions such as cancer in pregnant women. All of the women had abnormal noninvasive prenatal test results, and most frequently, more than one chromosomal abnormality was detected, which is a very unusual result. Many professional societies have recommended that NIPT be offered to pregnant women at high risk for having a fetus with autosomal (pertaining to a chromosome that is not a sex chromosome) aneuploidy, with follow-up diagnostic testing (amniocentesis or chorionic villus sampling) recommended to confirm a positive test result, according to background information in the article. In some cases, 10 babies turned out healthy but their mothers have been diagnosed with colon cancer, lymphoma or leukemia.
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The researchers have focused on eight of these women. It’s rare for a fetus to be viable with this profile, so the authors suggest that if the test shows multiple extra or missing chromosomes, maternal cancer should be considered as a possible cause. “The sensitivity and specificity of the verifi Prenatal Test to detect cancer is not now known, and further studies will be required to develop a test for this specific objective”. In women with cancer, the plasma sample also contains cancer DNA. In 8 of 10 reported cancer cases, Illumina scientists and physicians reviewed all the genome-wide sequencing data and identified nonspecific copy-number changes across multiple chromosomes, suggesting that these changes, when present in a woman whose fetal karyotype tests as normal, might represent a signal to the clinician to probe for the presence of cancer.
“When the test first came out we didn’t think about cancer being a possibility”.
“We need to do a better job up front to communicate with patients that we might find out something about their own health as well”, says Diana Bianchi of Tufts Medical Center, the first author of the paper, who is on an advisory panel for Illumina. She also added that more research needs to be conducted in order to help and guide physicians on how to deal with follow-up care and counsel women. “If it’s just a single abnormality, it’s much less likely to be cancer”, she said.
There are certain prenatal tests that can pinpoint towards something wrong with mothers-to-be. The research team published their findings online in the Journal of the American Medical Association (JAMA). She says she’s already heard of cases where genetic counselors have told women who get false positives for fetal abnormalities that they could have cancer. Accompanying videos and soundbites of Dr. Bianchi discussing the study can be viewed and downloaded here: http://ow.ly/PyK3L.
The study was funded by Illumina, which is a maker of one noninvasive prenatal test.
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“We continue to apply our technical and clinical expertise to the above liquid biopsy solutions in oncology and remain on track to release a research-use-only test for profile and circulating tumor DNA in the second half of 2015”, Sequenom chief executive William Welch said.
