Friedenreich C M
Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Canada.
Eur J Cancer Prev. 2001 Feb;10(1):15-32. doi: 10.1097/00008469-200102000-00003.
Epidemiological evidence implicating anthropometric risk factors in breast cancer aetiology is accumulating. For premenopausal women, breast cancer risk increases with increasing height, but decreases with higher weight or body mass index, and no association with increased central adiposity exists. For postmenopausal women, an increased risk of breast cancer is found with increasing levels of all the anthropometric variables including height, weight, body mass index, waist-hip ratio, waist circumference and weight gain. Weight loss appears to decrease risk, particularly if it occurs later in life. Breast size may be a risk factor for breast cancer, however, the current evidence is inconclusive. Several hypothesized biologic mechanisms exist to explain how anthropometric factors influence breast cancer risk. Obesity may increase levels of circulating endogenous sex hormones, insulin and insulin-like growth factors that all, in turn, increase breast cancer risk. Genetic predisposition to obesity and to specific body fat distributions are also implicated. With obesity, there are increased levels of fat tissue that can store toxins and can serve as a continuous source of carcinogens. Recommendations for future research on anthropometric factors and breast cancer are provided. Sufficient evidence exists to support strategies to avoid weight gain throughout life as a means of reducing postmenopausal breast cancer risk.
越来越多的流行病学证据表明，人体测量学风险因素与乳腺癌病因有关。对于绝经前女性，乳腺癌风险随身高增加而上升，但随体重或体重指数升高而降低，且与中心性肥胖增加无关。对于绝经后女性，包括身高、体重、体重指数、腰臀比、腰围和体重增加在内的所有人体测量变量水平升高，都会增加患乳腺癌的风险。体重减轻似乎会降低风险，尤其是在晚年发生时。乳房大小可能是乳腺癌的一个风险因素，然而，目前的证据尚无定论。有几种假设的生物学机制可解释人体测量因素如何影响乳腺癌风险。肥胖可能会增加循环内源性性激素、胰岛素和胰岛素样生长因子的水平，而这些都会反过来增加乳腺癌风险。肥胖和特定身体脂肪分布的遗传易感性也有牵连。肥胖时，脂肪组织水平升高，脂肪组织可储存毒素，并可作为致癌物的持续来源。本文还提供了关于人体测量因素与乳腺癌未来研究的建议。有充分证据支持采取终生避免体重增加的策略，以此作为降低绝经后乳腺癌风险的一种手段。
