WOMEN who smoke heavily before the menopause, especially prior to giving birth, may significantly increase their risk of developing breast cancer, research suggests.
A US study of almost 150,000 women found that breast cancer rates increased with higher levels of smoking among younger age groups.
“Smoking before menopause was positively associated with breast cancer risk,” the authors wrote in the journal Archives of Internal Medicine.
The size of the effect was “modest”, said the scientists led by Dr Fei Xue, from Harvard Medical School.
They added that smoking after the menopause slightly reduced the risk of breast cancer, and no significant association was seen between passive smoking, or light and moderate smoking, and breast cancer.
