Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, PO Box 19024, Seattle, WA 98109, USA.
Cancer Prev Res (Phila). 2012 Apr;5(4):515-21. doi: 10.1158/1940-6207.CAPR-12-0091. Epub 2012 Mar 5.
Obesity has been consistently associated with an increased risk of postmenopausal breast cancer in population-based studies. Conversely, obesity in such studies has been inversely associated with premenopausal breast cancer risk. In a report of data from two large chemoprevention trials, both of which enrolled women at a high risk of breast cancer, obesity was associated with only a modest, nonsignificantly increased risk of postmenopausal breast cancer and a surprising statistically significant 70% increased risk of premenopausal breast cancer (vs. normal weight). The discrepancies between these results and those from previous observational studies may be due to differences in study design and exposure ascertainment or due to inherent biologic differences whereby the obesity-breast cancer association differs for high-risk women in the clinical setting compared with general population, average-risk women in the observational setting.
肥胖症与基于人群的研究中的绝经后乳腺癌风险增加密切相关。相反，在这些研究中，肥胖与绝经前乳腺癌风险呈负相关。在两项大型化学预防试验数据的报告中，这两项试验均招募了乳腺癌高危女性，肥胖症仅与绝经后乳腺癌风险适度增加相关，且具有显著统计学意义的绝经前乳腺癌风险增加 70%（与正常体重相比）。这些结果与之前的观察性研究结果之间的差异可能是由于研究设计和暴露确定的差异，或者是由于内在的生物学差异，即与观察性研究中的一般风险、普通人群中的女性相比，临床环境中的高危女性的肥胖与乳腺癌的相关性不同。
