Jackson Sarah E, Heinrich Malgorzata, Beeken Rebecca J, Wardle Jane
Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, United Kingdom.
PLoS One. 2017 Jan 6;12(1):e0169173. doi: 10.1371/journal.pone.0169173. eCollection 2017.
Excess adiposity is a risk factor for poorer cancer survival, but there is uncertainty over whether losing weight reduces the risk. We conducted a critical review of the literature examining weight loss and mortality in overweight or obese cancer survivors.
We systematically searched PubMed and EMBASE for articles reporting associations between weight loss and mortality (cancer-specific or all-cause) in overweight/obese patients with obesity-related cancers. Where available, data from the same studies on non-overweight patients were compared.
Five articles describing observational studies in breast cancer survivors were included. Four studies reported a positive association between weight loss and mortality in overweight/obese survivors, and the remaining study observed no significant association. Results were similar for non-overweight survivors. Quality assessment indicated high risk of bias across studies.
There is currently a lack of observational evidence that weight loss improves survival for overweight and obese cancer survivors. However, the potential for bias in these studies is considerable and the results likely reflect the consequences of disease-related rather than intentional weight loss. There is a need for stronger study designs, incorporating measures of intentionality of weight loss, and extended to other cancers.
肥胖是癌症患者生存率较低的一个风险因素，但体重减轻是否能降低风险尚不确定。我们对有关超重或肥胖癌症幸存者体重减轻与死亡率的文献进行了批判性综述。
我们系统检索了PubMed和EMBASE，以查找报告超重/肥胖且患有肥胖相关癌症的患者体重减轻与死亡率（癌症特异性或全因死亡率）之间关联的文章。如有可用数据，对同一研究中关于非超重患者的数据进行了比较。
纳入了五篇描述乳腺癌幸存者观察性研究的文章。四项研究报告超重/肥胖幸存者体重减轻与死亡率之间存在正相关，其余一项研究未观察到显著关联。非超重幸存者的结果类似。质量评估表明各研究存在较高的偏倚风险。
目前缺乏观察性证据表明体重减轻能提高超重和肥胖癌症幸存者的生存率。然而，这些研究中存在相当大的偏倚可能性，结果可能反映的是疾病相关而非刻意体重减轻的后果。需要采用更强有力的研究设计，纳入体重减轻意图的衡量指标，并扩展到其他癌症。
