Kruk Joanna
Institute of Physical Education, Faculty of Natural Sciences, University of Szczecin, Al. Piastów 40 b/6, 71-065 Szczecin, Poland.
Cancer Detect Prev. 2007;31(1):18-28. doi: 10.1016/j.cdp.2006.12.003. Epub 2007 Feb 12.
The association between breast cancer and lifetime histories of physical activity was studied to determine whether exercise may reduce development of this cancer.
The case-control study was based on 250 women living in the Region of Western Pomerania with histological confirmed breast cancer operated during 1999-2003 in the Szczecin hospitals, and 301 controls, free of any cancer diagnosis, aged 35-75 years. Physical activity was assessed using a self-administered questionnaire with questions on type of activity, duration, frequency, and intensity for each type of activity. Data on physical activity from exercise/sports, household and outdoor chores, and occupational activity separately throughout a woman's lifetime were collected. Recreational physical activity was examined for the four age periods (14-20, 21-34, 35-50, and after the age of 50 years). Logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CI) and a full assessment of confounding was included in analysis.
Lifetime total physical activity among all women was associated with a reduced breast cancer risk; after controlling for potential confounders the multivariate ORs associated with <110, 110-150, and >150 metabolic equivalent (MET)-hours/week/year were 1.00 (referent), 0.60 (95% CI: 0.60-1.06), and 0.43 (95% CI: 0.25-0.75), respectively (P(trend)=0.004). Analyses by type of lifetime activity for household and recreational activities revealed significant risk reductions: 1.00 (referent); 0.51, 95% CI: 0.29-0.87; 0.54, 95% CI: 0.31-0.94 (P(trend)=0.002), and 1.00 (referent); 0.54, 95% CI: 0.31-0.94; 0.40, 95% CI: 0.22-0.70 (P(trend)<0.001), respectively. For lifetime occupational activity a modest association could not be ruled out when measured the activity by average annual hours/week; the ORs were 0.51, 95% CI: 0.29-0.91, and 0.58, 95% CI: 0.33-1.00, the inverse trend in risk was not significant (P(trend)=0.51). Women who started recreational activity after age of 20 years had much more higher breast cancer risk than either those who were active between ages 14 and 20 years and were inactive after age 20 years or continued their activity throughout adult life.
These data are in concordance with the hypothesis that lifetime total physical activity is associated with decreased breast cancer risk. They also suggest that recreational physical activity at ages 14-20 years is the most beneficial. In addition, these findings confirm the majority of previous reports which implicated physical inactivity as important risk factor for breast cancer.
研究乳腺癌与终生身体活动史之间的关联，以确定运动是否可降低该癌症的发病风险。
这项病例对照研究基于250名居住在西波美拉尼亚地区、于1999年至2003年期间在什切青医院接受组织学确诊并接受手术治疗的乳腺癌女性，以及301名年龄在35至75岁、未患任何癌症的对照者。使用一份自填式问卷评估身体活动情况，问卷涉及活动类型、持续时间、频率以及每种活动类型的强度等问题。收集了女性一生中运动/体育活动、家务和户外杂务以及职业活动的身体活动数据。对四个年龄阶段（14至20岁、21至34岁、35至50岁以及50岁之后）的娱乐性身体活动进行了检查。采用逻辑回归计算比值比（OR）和95%置信区间（CI），并在分析中全面评估混杂因素。
所有女性的终生总体身体活动与降低的乳腺癌风险相关；在控制潜在混杂因素后，与每周/每年代谢当量（MET）小时数<110、110至150以及>150相关的多变量OR分别为1.00（参照值）、0.60（95% CI：0.60至1.06）和0.43（95% CI：0.25至0.75）（P趋势 = 0.004）。按终生活动类型对家务和娱乐活动进行的分析显示风险显著降低：1.00（参照值）；0.51，95% CI：0.29至0.87；0.54，95% CI：0.31至0.94（P趋势 = 0.002），以及1.00（参照值）；0.54，95% CI：0.31至0.94；0.40，95% CI：0.22至0.70（P趋势<0.001）。对于终生职业活动，以平均每年每周工作小时数衡量活动时，不能排除适度关联；OR分别为0.51，95% CI：0.29至0.91，以及0.58，95% CI：0.33至1.00，风险的反向趋势不显著（P趋势 = 0.51）。20岁之后开始进行娱乐性活动的女性患乳腺癌的风险比那些在14至20岁期间活跃但20岁之后不活动或在成年期持续活动的女性高得多。
这些数据与终生总体身体活动与降低乳腺癌风险相关的假设一致。它们还表明14至20岁的娱乐性身体活动最为有益。此外，这些发现证实了之前的大多数报告，这些报告认为身体不活动是乳腺癌的重要风险因素。
