Cust Anne E
Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, School of Population Health, The University of Melbourne, Level 1, 723 Swanston Street, Melbourne, VIC, 3010, Australia.
Recent Results Cancer Res. 2011;186:159-85. doi: 10.1007/978-3-642-04231-7_7.
This chapter reviews the findings from epidemiologic studies of the associations of physical activity with gynecologic cancers, including those of the endometrium, ovaries, and cervix, and the biologic mechanisms mediating the associations. The epidemiologic evidence to date suggests that physical activity probably protects against endometrial cancer, with a risk reduction of about 20-30% for those with the highest levels of physical activity compared to those with the lowest levels, and that light to moderate physical activity including housework, gardening, or walking for transportation may reduce risk. The role of physical activity in ovarian cancer development remains uncertain, as findings from these studies have been inconsistent with about half the studies suggesting physical activity modestly decreases risk and about half the studies suggesting no association. A recent meta-analysis of studies examining recreational physical activity with ovarian cancer risk estimated a 20% reduced risk for the most active versus least active women. There is mounting evidence that sedentary behaviors such as sitting time probably increase risk of endometrial and ovarian cancers. Overall, there is insufficient evidence to draw a conclusion on a possible role of physical activity in the development of cervical cancer, although a modest influence on risk is possible through effects on sex steroid hormones and immune function. The biologic evidence provides strong support for a protective role of physical activity on cancer of the endometrium, and moderate support for cancer of the ovaries, as these cancers have a strong hormonal etiology. The more established biologic mechanisms that are supported by epidemiologic and experimental data involve endogenous sex hormone levels, insulin-mediated pathways, and maintenance of energy balance.In this chapter, we will discuss the evidence for an association of physical activity with gynecologic cancers including those of the endometrium, ovaries, and cervix. Cancers of the endometrium and ovaries have a strong hormonal etiology (Risch 1998; Kaaks et al. 2002; Lukanova and Kaaks 2005), and physical activity has been postulated as a potential modifiable risk factor for prevention of these cancers because it can influence circulating hormone levels, energy balance, and insulin-mediated pathways that are thought to be important mediators underlying the associations. Few studies have evaluated the association of physical activity with cervical cancer because the main causal factor is infection with certain types of human papillomavirus (HPV), although other hormonal and immune factors are also thought to play a role (Smith et al. 2003; Waggoner 2003). We review the findings from epidemiologic studies that have examined the associations of physical activity with gynecologic cancers, and the biologic mechanisms that might mediate the associations.
本章回顾了关于身体活动与妇科癌症（包括子宫内膜癌、卵巢癌和宫颈癌）关联的流行病学研究结果，以及介导这些关联的生物学机制。迄今为止的流行病学证据表明，身体活动可能对子宫内膜癌具有预防作用，与身体活动水平最低者相比，身体活动水平最高者患子宫内膜癌的风险降低约20%-30%，而且包括家务劳动、园艺或步行上下班在内的轻度至中度身体活动可能会降低风险。身体活动在卵巢癌发生中的作用仍不确定，因为这些研究的结果并不一致，大约一半的研究表明身体活动适度降低风险，另一半研究则表明无关联。最近一项对研究休闲身体活动与卵巢癌风险的研究进行的荟萃分析估计，最活跃女性与最不活跃女性相比，患卵巢癌的风险降低20%。越来越多的证据表明，久坐行为（如久坐时间）可能会增加子宫内膜癌和卵巢癌的风险。总体而言，虽然身体活动可能通过对性甾体激素和免疫功能的影响对宫颈癌风险产生适度影响，但目前尚无足够证据就身体活动在宫颈癌发生中的可能作用得出结论。生物学证据有力支持了身体活动对子宫内膜癌的预防作用，对卵巢癌的预防作用有一定支持，因为这些癌症具有强烈的激素病因。流行病学和实验数据支持的更成熟的生物学机制涉及内源性性激素水平、胰岛素介导的途径以及能量平衡的维持。在本章中，我们将讨论身体活动与妇科癌症（包括子宫内膜癌、卵巢癌和宫颈癌）关联的证据。子宫内膜癌和卵巢癌具有强烈的激素病因（里斯奇，1998；卡克斯等人，2002；卢卡诺娃和卡克斯，2005），身体活动被认为是预防这些癌症的一个潜在可改变风险因素，因为它可以影响循环激素水平、能量平衡以及胰岛素介导的途径，而这些被认为是潜在关联的重要介导因素。很少有研究评估身体活动与宫颈癌的关联，因为主要病因是某些类型的人乳头瘤病毒（HPV）感染，尽管其他激素和免疫因素也被认为起作用（史密斯等人，2003；瓦戈纳，2003）。我们回顾了研究身体活动与妇科癌症关联的流行病学研究结果，以及可能介导这些关联的生物学机制。
