cancer research
Research has proved that a mother can pass her cancer cells onto her unborn baby.
Though the cases are very rare cases where a mother and child to share the same cancer, as in theory the child's immune system should block the cancer.
The study appears in Proceedings of the National Academy of Sciences by British scientists who have analyised data of one such case show the cells which caused leukaemia in the child could only have come from the mother.
The research was really important 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 new treatments can be developed
Whether it is possible for a mother to "infect" her unborn child with cancer has puzzled scientists for many years.
In theory any cancer cells that manage to cross the placenta into the baby's bloodstream should be destroyed by the child's immune system.
But the team looked at 17 recorded cases of a mother and baby appearing to share the same cancer most frequently leukaemia or melanoma.
The latest study focused on a Japanese woman and her baby, who both developed leukaemia.
The researcher using an advanced genetic fingerprinting technique to prove that the leukaemia cells found in the baby had originated from the mother. They concluded that both patients' leukaemic cells carried an identical mutated cancer gene.
However, they also showed that the child had not inherited this gene from its mother - meaning it could not have developed this type of leukaemia in isolation.
The research then studied how the cancer cells could have neutralised the baby's immune system, finding that the cancer cells lacked some DNA which played a crucial role in giving them their own specific molecular signature.
Without this identifying molecular sign, the child's immune system was not able to mark the cells as foreign and thus target them for destruction.
Lead researcher at the Institute of Cancer Research, said in the publication: "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 foetus and succeeded in implanting because they were invisible to the immune system.
"We are pleased to have resolved this longstanding puzzle. But we stress 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."
Cancer Research UK, stressed that it was extremely unusual for cancer to pass from a mother to her baby.
A spokesperson said The research was really important 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 new treatments can be developed.
The charity stressed that 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.
Dr David Grant, scientific director at Leukaemia Research, which part-funded the study, said it should help work to harness the power of the immune system to first cure and then protect patients from leukaemia.
Tagged in Cancer Research UK