文章：

体育活动与癌症之间的联系机制

Mechanisms linking physical activity with cancer

原文发布日期：2008-03-01

DOI: 10.1038/nrc2325

类型: Review Article

开放获取: 否

要点：

1. Regular moderate-intensity or greater physical activity is associated with a reduced risk of several types of cancer, including cancers of the breast, colon and endometrium. For several cancers, engaging in longer exercise sessions, or exercising with greater intensity or for more years, produces greater reductions in cancer risk.
2. Recent findings indicate that women with a history of breast cancer who engage in more than 9 metabolic equivalent (MET)·h/week of recreational physical activity after breast cancer diagnosis, which corresponds to approximately 2–3 h/week of brisk walking, had a significantly lower risk of death or breast cancer recurrence than women who were inactive. Similarly, men or women who are active after a diagnosis of colon cancer appear to have improved prognosis compared with sedentary individuals.
3. Physical activity effects on menstrual function and sex hormones might explain a link between increased physical activity and reduced risk for breast and endometrial cancers. Athletes and physically active premenopausal women have delayed onset of menses, fewer ovulatory cycles and lower circulating levels of oestrogen and progesterone, all factors that are related to breast or endometrial cancer risk.
4. Studies in postmenopausal women indicate that physical activity might affect postmenopausal breast cancer and endometrial cancer risk by reducing body fat, thereby lowering circulating levels of oestrogens and androgens.
5. Insulin resistance, hyperinsulinaemia, hyperglycaemia and type 2 diabetes have been linked to increased risk of breast, colon, pancreas and endometrial cancers. Physical activity improves insulin resistance, reduces hyperinsulinaemia and reduces risk for diabetes, which could explain the link between increased physical activity and reduced risk for these cancers.
6. Increased levels of pro-inflammatory factors and decreased levels of anti-inflammatory factors have been linked with increased cancer risk. Physical activity might reduce systemic inflammation alone or in combination with reduction in body weight or composition through reducing inflammatory cytokines in adipose tissue.
7. Support for an effect of physical activity on the cancer process comes from smaller randomized clinical trials. If definitive evidence from larger clinical trials is obtained to show that increased physical activity can prevent certain cancers, or can improve prognosis, it would be an excellent public-health intervention for reducing the impact of cancer at relatively low cost and risk.

要点翻译：

1. 定期进行中等或更高强度的体育活动可降低多种癌症风险，包括乳腺癌、结肠癌和子宫内膜癌。对于某些癌症而言，运动时间更长、强度更高或坚持年限更久，对癌症风险的降低效果更为显著。
2. 最新研究显示，有乳腺癌病史的女性在确诊后若每周进行超过9代谢当量小时（MET·h）的休闲体育活动（相当于每周快走2-3小时），其死亡或乳腺癌复发的风险显著低于不活动的患者。同样，结肠癌确诊后保持活动的男女患者，其预后似乎也优于久坐患者。
3. 体力活动对月经功能及性激素的影响可解释其与降低乳腺癌和子宫内膜癌风险之间的关联。运动员和经常运动的绝经前女性会出现月经初潮延迟、排卵周期减少以及雌激素和孕激素循环水平降低，这些因素均与乳腺癌和子宫内膜癌风险相关。
4. 针对绝经后女性的研究表明，体力活动可能通过减少体脂来降低雌激素和雄激素的循环水平，从而影响绝经后乳腺癌和子宫内膜癌的发病风险。
5. 胰岛素抵抗、高胰岛素血症、高血糖和2型糖尿病与乳腺癌、结肠癌、胰腺癌和子宫内膜癌的风险升高相关。体力活动能改善胰岛素抵抗、降低高胰岛素血症并减少糖尿病风险，这可以解释增加体力活动与降低上述癌症风险之间的关联。
6. 促炎因子水平升高和抗炎因子水平降低与癌症风险增加有关。体力活动可能通过减少脂肪组织中的炎性细胞因子，单独或联合体重/体脂的降低来减轻全身性炎症。
7. 一些较小规模的随机临床试验为体力活动影响癌症进程提供了佐证。若能从更大规模的临床试验中获得确凿证据，证明增加体力活动可以预防特定癌症或改善预后，这将成为一项极佳的公卫干预措施——以较低成本和风险减轻癌症带来的负担。

英文摘要：

About 25% of cancer cases globally are due to excess weight and a sedentary lifestyle. Physical activity may decrease risk for various cancers by several mechanisms, including decreasing sex hormones, metabolic hormones and inflammation, and improving immune function. The level of physical activity might also be associated with prognosis among individuals with cancer. Randomized clinical trials have shown that physical activity interventions can change biomarkers of cancer risk. Observational studies can also provide useful information on mechanisms that might link physical activity to cancer.

摘要翻译： 

全球约25%的癌症病例归因于超重和久坐不动的生活方式。体力活动可能通过多种机制降低多种癌症的风险，包括降低性激素、代谢激素和炎症水平，以及改善免疫功能。体力活动水平也可能与癌症患者的预后相关。随机临床试验表明，体力活动干预可改变癌症风险的生物标志物。观察性研究也可为体力活动与癌症之间可能存在的机制提供有用信息。

原文链接：

Mechanisms linking physical activity with cancer