McTiernan Anne, Kooperberg Charles, White Emily, Wilcox Sara, Coates Ralph, Adams-Campbell Lucile L, Woods Nancy, Ockene Judith
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
JAMA. 2003 Sep 10;290(10):1331-6. doi: 10.1001/jama.290.10.1331.
Women who are physically active have a decreased risk for breast cancer, but the types, amounts, and timing of activity needed are unknown.
To prospectively examine the association between current and past recreational physical activity and incidence of breast cancer in postmenopausal women.
DESIGN, SETTING, AND PATIENTS: Prospective cohort study in 74 171 women aged 50 to 79 years who were recruited by 40 US clinical centers from 1993 through 1998.
Incident invasive and in situ breast cancer.
We documented 1780 newly diagnosed cases of breast cancer over a mean follow-up of 4.7 years. Compared with less active women, women who engaged in regular strenuous physical activity at age 35 years had a 14% decreased risk of breast cancer (relative risk [RR], 0.86; 95% confidence interval [CI], 0.78-0.95). Similar but attenuated findings were observed for strenuous physical activity at ages 18 years and 50 years. An increasing total current physical activity score was associated with a reduced risk for breast cancer (P =.03 for trend). Women who engaged in the equivalent of 1.25 to 2.5 hours per week of brisk walking had an 18% decreased risk of breast cancer (RR, 0.82; 95% CI, 0.68-0.97) compared with inactive women. Slightly greater reduction in risk was observed for women who engaged in the equivalent of 10 hours or more per week of brisk walking. The effect of exercise was most pronounced in women in the lowest tertile of body mass index (BMI) (<24.1), but also was observed for women in the middle tertile of BMI (24.1-28.4).
These data suggest that increased physical activity is associated with reduced risk for breast cancer in postmenopausal women, longer duration provides most benefit, and that such activity need not be strenuous.
进行体育活动的女性患乳腺癌的风险降低，但所需的活动类型、运动量和时间尚不清楚。
前瞻性研究绝经后女性当前和过去的休闲体育活动与乳腺癌发病率之间的关联。
设计、地点和患者：对1993年至1998年期间由美国40个临床中心招募的74171名年龄在50至79岁之间的女性进行前瞻性队列研究。
侵袭性和原位乳腺癌的发病情况。
在平均4.7年的随访中，我们记录了1780例新诊断的乳腺癌病例。与活动较少的女性相比，35岁时进行定期剧烈体育活动的女性患乳腺癌的风险降低了14%（相对风险[RR]，0.86；95%置信区间[CI]，0.78 - 0.95）。在18岁和50岁时进行剧烈体育活动也观察到了类似但较弱的结果。当前总的体育活动得分增加与乳腺癌风险降低相关（趋势P = 0.03）。与不活动的女性相比，相当于每周快走1.25至2.5小时的女性患乳腺癌的风险降低了18%（RR，0.82；95%CI，0.68 - 0.97）。对于相当于每周快走10小时或更长时间的女性，观察到风险降低幅度略大。运动的效果在体重指数（BMI）最低三分位数（<24.1）的女性中最为明显，但在BMI处于中间三分位数（24.1 - 28.4）的女性中也有观察到。
这些数据表明，体育活动增加与绝经后女性乳腺癌风险降低相关，持续时间越长益处越大，且这种活动不一定需要剧烈。
