A team of researchers from the Tufts Medical Center has been working with non-invasive screening methods which could detect cancer in mothers-to-be. Detecting maternal cancer via such non-invasive tests may be extremely valuable, as many prenatal tests, such as the one for Down syndrome, may return false positives when the mother-to-be has an undiagnosed cancer.
The study was published in Tuesday’s issue of JAMA and involved eight cases of false positive results that had come back from foetuses suspected of having genetic abnormalities. What the researchers concluded, however, was that these false readings had not originated with the unborn children, but with the altered DNA of the mother.
The study authors explain that in the case of cancer patients, certain strands of DNA may stem from cells that have died and released the altered DNA (mutated DNA) into the woman’s bloodstream.
When presented with the news that their babies may have certain chromosomal abnormalities and that most babies with such abnormalities don’t survive, mothers rarely think about themselves. But, as with the case of one study participant, two months after receiving the results of the prenatal tests, she was admitted to the hospital with shoulder pain. She discovered she had Non-Hodgkin’s lymphoma.
For her, it was her own cancer providing the false positive results of the genetic tests and not the fetus.
Follow-up tests proved that the baby was fine, however, study authors explain that false positives in the case of the mother-to-be may indicate a need for further testing, in the case of the mother and not the fetus.
Though unexpected, the results of the study are very promising, Dr. Diana Bianchi, Mother Infant Research Institute at Tufts, explains.
On the one side, it suggests that false positives should always be checked and re-checked with additional tests, as they may originate from the mother and not her unborn child. On the other, it also points towards a need to investigate whether the mother-to-be may be suffering from any type of cancer.
According to Dr. Robert Green, Brigham and Women’s Hospital geneticist, the study may foreshadow an exciting future of prenatal tests that could screen for cancer even in its earliest stages.
“The exciting thing to me about this is that it could rapidly add to the momentum already underway in developing blood-based genetic screening measures for hidden cancers,” he said.
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