Cancer defence: According to the researchers, foetal cells could remain in the mother for the duration of her life, offering protection against cancer.
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WASHINGTON DC: Having children could reduce the risk of breast cancer because cells with protective characteristics are transferred from a foetus to its mother.
U.S. researchers studied 82 women, 35 of whom had been diagnosed with breast cancer, to test a theory that foetal cells, which have taken up residence in the mother's body – a process called 'foetal micro-chimerism' – protect against breast cancer.
Protective benefits
"Most studies have looked at autoimmune diseases where chimerism has been shown to be bad, but so many women harbour micro-chimerism after pregnancy in detectable levels that I reasoned there must be some reason why nature decided this must be a good thing to do," said lead researcher Vijayakrishna K. Gadi of the University of Washington in Seattle.
"Perhaps it's this function of clearing cancer cells from your body. Another possibility is that it could participate in tissue repair," he said.
As they detail in the current issue of the journal Cancer Research, the scientists searched blood samples from each the female participants of the study for male DNA, which was easier to isolate than DNA from a female child.
"I don't have any intrinsic reason to believe that a male child would be any more protective than a female child," Gadi stressed, adding that the researchers hope to go on to conduct studies into foetal chimerism from all sources.
Stem cell link
The results revealed that about 14 per cent of all women in the breast cancer group had DNA from their male children in their bloodstream, compared with 43 per cent of women in the non-breast cancer group.
"My hypothesis was that maybe foetal cells can get into a mother and recognise a pre-cancer breast cancer cell and kill it before it becomes an active cancer," Gadi said. "We have other studies from our group where we believe stem cells are really what are coming over, establishing themselves in various tissues and reproducing themselves," he added, urging follow-up studies.
According to the researchers, foetal cells could remain in the mother for the duration of her life, offering protection against cancer.
