BOSTON, Jan. 5 There's no single way to reduce the risk for breast cancer, but a combination of approaches could make a difference, suggests a U.S. newsletter.The Harvard Women's Health Watch newsletter says there are several factors that could affect breast-cancer risk:-- Studies show that weight gain is a risk factor for breast cancer after menopause. The link is estrogen, which is believed to promote the development of breast cancer. Fat tissue converts precursors in the body into estrogen, keeping the hormone in circulation even when ovarian production stops at menopause.-- A few drinks per week raise the risk for breast cancer.-- Exercise may help prevent breast cancer and its recurrence in a few ways, including by keeping weight down and decreasing the amount of estrogen in breast tissue.-- Vitamin D helps protect against several types of cancer, including breast cancer.-- Because lifetime exposure to estrogen is a risk factor for breast cancer, there's concern about women's use of birth-control pills and postmenopausal hormones.-- Breast density is trumped only by age and certain gene mutations in the hierarchy of risk factors.-- Taking the anti-estrogen drug tamoxifen or raloxifene may cut the incidence of breast cancer for women with an increased risk.Copyright 2007 by UPI
