(BOSTON) -- A new study published in the Archives of Internal Medicine suggests that heavy smokers of childbearing age -- particularly women who have never been pregnant -- are at higher risk of developing breast cancer.
Researchers from Brigham and Women's Hospital and Harvard Medical School examined the medical records of 111,140 women over a 30-year period. These observations led researchers to conclude that smoking cigarettes in high quantities over a longer time period was associated with breast cancer among pre-menopausal women.
Of the women studied, nearly 9,000 developed breast cancer while pre-menopausal heavy smokers had a six percent higher rate of malignancy.
Researchers added that second-hand smoke exposure did not appear to advance breast cancer risk, though it was difficult to observe. Light and moderate smoking also did not seem to increase risk for breast cancer.
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