Department of Cancer Epidemiology and Prevention Research, Cancer Control Alberta, Alberta Health Services, Holy Cross Centre, Room 513C, Box ACB, 2210 2nd Street S.W., Calgary, AB, T2S 3C3, Canada.
Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
BMC Cancer. 2018 Jan 11;18(1):71. doi: 10.1186/s12885-017-3970-5.
Physical activity is consistently associated with a reduced risk of colorectal cancer in epidemiologic studies. This association among higher risk subgroups, such as those with a first-degree family history of colorectal cancer or high body mass index remains unclear.
We searched MEDLINE for studies examining physical activity and colorectal cancer risk among higher risk subgroups through July 11, 2017. Fifteen and three studies were eligible for inclusion for body mass index and first-degree family history of colorectal cancer subgroups, respectively. Estimates of the highest to lowest comparison of physical activity for each subgroup of risk were pooled using random-effects models.
The pooled associations of physical activity and colorectal cancer risk for those without and with a first-degree family history of colorectal cancer were 0.56 (95% confidence interval (CI) = 0.39-0.80) and 0.72 (95% CI = 0.39-1.32), respectively (p = 0.586). The pooled associations of physical activity and colorectal cancer risk for the low and high body mass index groups were 0.74 (95% CI = 0.66-0.83) and 0.65 (95% CI = 0.53-0.79), respectively (p = 0.389).
Overall, a stronger relative risk of physical activity on colorectal cancer risk was observed in the higher body mass index group, although the difference was not statistically significant, suggesting an added benefit of physical activity as a cancer prevention strategy in population groups with strong risk factors for colorectal cancer. Additional research among these subgroups is warranted.
在流行病学研究中，身体活动与结直肠癌风险降低相关。然而，对于身体质量指数较高或一级亲属有结直肠癌病史的高危亚组，这种关联尚不清楚。
我们检索了 MEDLINE 数据库，以寻找截至 2017 年 7 月 11 日评估身体活动与高危亚组（如一级亲属有结直肠癌病史或身体质量指数较高）结直肠癌风险之间关系的研究。分别有 15 项和 3 项研究符合纳入身体质量指数和一级亲属结直肠癌史亚组的标准。使用随机效应模型对每个风险亚组的最高与最低身体活动水平的比值进行了汇总。
对于没有一级亲属结直肠癌病史和有一级亲属结直肠癌病史的个体，身体活动与结直肠癌风险的关联分别为 0.56（95%置信区间：0.39-0.80）和 0.72（95%置信区间：0.39-1.32）（p=0.586）。对于身体质量指数较低和较高的个体，身体活动与结直肠癌风险的关联分别为 0.74（95%置信区间：0.66-0.83）和 0.65（95%置信区间：0.53-0.79）（p=0.389）。
总体而言，身体活动对结直肠癌风险的相对风险在身体质量指数较高的组中更强，尽管差异无统计学意义，但这表明身体活动作为结直肠癌高危人群的癌症预防策略具有额外的益处。这些亚组需要进一步的研究。
