New research shows that it is possible for a mother’s cancer cells to be passed to her unborn child, even though such a transmission is unlikely, BBC News reported.
Experts say that while there are very rare cases where a mother and child appear to share the same cancer, in theory the child’s immune system should block the cancer.
A British-led team of scientists showed that one such case revealed the cells that caused leukemia in the child could only have come from the mother.
The question as to whether a mother can “infect” her unborn child with cancer has puzzled scientists for 100 years. Experts initially believed the child’s immune system would destroy any cancer cells that manage to cross the placenta into the baby’s bloodstream.
At least 17 cases of a mother and baby appearing to share the same cancer ““ usually leukemia or melanoma ““ have been recorded.
The most recent study highlighted a Japanese woman and her baby, who both developed leukemia. An advanced genetic fingerprinting technique was used to prove that the leukemia cells found in the baby had originated from the mother.
Scientists were able to show that both patients’ leukemia cells carried an identical mutated cancer gene. But they also showed that the child had not inherited this gene from its mother ““ meaning it could not have developed this type of leukemia in isolation.
The team then looked at how the cancer cells could have neutralized the baby’s immune system and discovered that the cancer cells lacked some DNA that played a crucial role in giving them their own specific molecular identity.
This resulted in the child’s immune system being unable to recognize the cells as foreign, and therefore not being mobilized to attack them.
“It appears that in this and, we presume, other cases of mother-to-offspring cancer, the maternal cancer cells did cross the placenta into the developing fetus and succeeded in implanting because they were invisible to the immune system,” said lead researcher Professor Mel Greaves of the Institute of Cancer Research.
Greaves said they were pleased to have resolved this longstanding puzzle, but he stressed that such mother-to-offspring transfer of cancer is exceedingly rare and the chances of any pregnant woman with cancer passing it on to her child are remote.
It is extremely unusual for cancer to pass from a mother to her baby, according to Professor Peter Johnson, chief clinician at the charity Cancer Research UK.
“This is really important research as it adds to the evidence that cancers need to evade the immune system before they can grow, giving hope that by alerting a patient’s immune system to a cancer we can develop new types of treatment,” he said.
Johnson recommends that any women needing cancer treatment around the time of having a baby who are worried about this research should speak to the specialists looking after them for advice.
The full study was published in Proceedings of the National Academy of Sciences.
—
On the Net:
Comments