WASHINGTON, Nov. 6 (Xinhua) -- Women who suffer from migraines may take at least some comfort in a recent, first-of-its-kind study that suggests a history of such headaches is associated with a significantly lower risk of breast cancer.

    A research team at Fred Hutchinson Cancer Research Center in Seattle, Washington, reported the findings in the November issue of Cancer Epidemiology, Biomarkers and Prevention.

    "We found that, overall, women who had a history of migraines had a 30 percent lower risk of breast cancer compared to women who did not have a history of such headaches," said the authors. The findings may point to new ways of reducing a woman's risk for breast cancer, they said.

    In particular, a history of migraines appears to reduce the risk of the most common subtypes of breast cancer: those that are estrogen-receptor and/or progesterone-receptor positive. Such tumors have estrogen and/or progesterone receptors, or docking sites, on the surface of their cells, which makes them more responsive to hormone-blocking drugs than tumors that lack such receptors.

    The biological mechanism behind the association between migraines and breast cancer is not fully known, but researchers suspect that it has to do with fluctuations in levels of circulating hormones.

    Migraines seem to have a hormonal component in that they occur more frequently in women than in men, and some of their known triggers are associated with hormones, the authors said.

    While these results need to be interpreted with caution, they point to a possible new factor that may be related to breast-cancer risk. "This gives us a new avenue to explore the biology behind risk reduction. Hopefully this could help stimulate other ideas and extend what we know about the biology of breast cancer," the authors said.