Institute of Physical Education, University of Szczecin , Szczecin, Poland.
J Sports Sci Med. 2010 Jun 1;9(2):311-9. eCollection 2010.
Regular recreational physical activity has been found to be associated with a decrease in breast cancer risk in women in the majority of epidemiologic studies, but research findings are inconsistent regarding the intensity of activity and timing in life. To address these issues the relations of moderate and vigorous intensity recreational physical activity during ages 14-20, 21-34, 35-50, and over age 50 years to pre- and postmenopausal breast cancer risk were examined. A case-control study of 858 women, with histological confirmation of invasive breast cancer, and 1085 controls, free of any cancer diagnosis, all subjects aged 28-79 years was conducted in the Region of Western Pomerania (Poland). Physical activity was assessed using a self-administered questionnaire with questions on type of activity, duration, frequency, and intensity for each type of activity. Odds ratios (OR) and 95% confidence intervals (CI) of breast cancer associated with physical activity were calculated using unconditional logistic regression. Vigorous physical activity at ages 14-20 and 21-34 years lowered breast cancer risk by at least 35% in premenopausal women and by at least 51% in postmenopausal women for the highest versus lowest quartiles of the activity. The risk was also reduced in postmenopausal women who reported on average more than 1.74 hours per week of vigorous intensity recreational activity in ages >50 years (OR = 0.58; 95%CI = 0.27-0.97; P for trend = 0.013). For moderate activity the relationships remained statistically significant only in postmenopausal women active during ages 14- 20 years. The results indicate also a plausible risk reduction among premeno-pausal women. These results support the hypothesis that recrea-tional activity, particularly done early in life, is associated with a decrease in the invasive breast cancer risk in postmenopausal women. Among premenopausal women, only vigorous forms of activity may significantly decrease the risk. Key pointsRecreational physical activity of vigorous intensity during ages 14-20 and 21-34 years protect against breast cancer regardless of menopausal status.Vigorous recreational physical activity at ages >50 years was also associated with reduced postmeno-pausal breast cancer risk.The risk reduction was also observed among post-menopausal women engaged in recreational physical activity of moderate intensity at ages 14-20 years.
有研究发现，有规律的休闲体育活动与大多数流行病学研究中女性乳腺癌风险降低有关，但关于活动强度和生命阶段的研究结果并不一致。为了解决这些问题，本研究分析了女性 14-20 岁、21-34 岁、35-50 岁和 50 岁以上时的中等和剧烈强度休闲体育活动与绝经前和绝经后乳腺癌风险的关系。该研究是在波兰西波美拉尼亚地区（波兰）进行的一项病例对照研究，共纳入 858 名经组织学证实患有浸润性乳腺癌的女性患者（病例组）和 1085 名无任何癌症诊断的女性（对照组），所有参与者年龄均在 28-79 岁之间。采用自我管理式问卷评估体育活动情况，问卷内容包括活动类型、持续时间、频率和每种活动的强度。采用非条件逻辑回归计算与体育活动相关的乳腺癌比值比（OR）和 95%置信区间（CI）。在最高四分位组和最低四分位组中，14-20 岁和 21-34 岁时剧烈运动可使绝经前女性乳腺癌风险降低至少 35%，使绝经后女性乳腺癌风险降低至少 51%。在年龄>50 岁时每周平均进行超过 1.74 小时剧烈强度休闲活动的绝经后女性中，风险也降低了（OR=0.58；95%CI=0.27-0.97；趋势 P 值=0.013）。对于中等强度运动，仅在 14-20 岁时活跃的绝经后女性中，相关性仍具有统计学意义。在绝经前女性中，仅剧烈运动形式可能会显著降低风险。这些结果支持了这样一种假说，即休闲活动，特别是早期生活中的活动，与绝经后女性的浸润性乳腺癌风险降低有关。在绝经前女性中，只有剧烈活动形式可能会显著降低风险。主要发现14-20 岁和 21-34 岁时剧烈强度的休闲体育活动可预防乳腺癌，与绝经状态无关。年龄>50 岁时进行剧烈的休闲体育活动也与绝经后乳腺癌风险降低有关。14-20 岁时进行中等强度休闲体育活动的绝经后女性也观察到风险降低。
