Renehan Andrew G, Tyson Margaret, Egger Matthias, Heller Richard F, Zwahlen Marcel
Department of Surgery, School of Cancer Studies, University of Manchester, UK.
Lancet. 2008 Feb 16;371(9612):569-78. doi: 10.1016/S0140-6736(08)60269-X.
Excess bodyweight, expressed as increased body-mass index (BMI), is associated with the risk of some common adult cancers. We did a systematic review and meta-analysis to assess the strength of associations between BMI and different sites of cancer and to investigate differences in these associations between sex and ethnic groups.
We did electronic searches on Medline and Embase (1966 to November 2007), and searched reports to identify prospective studies of incident cases of 20 cancer types. We did random-effects meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of cancer associated with a 5 kg/m2 increase in BMI.
We analysed 221 datasets (141 articles), including 282,137 incident cases. In men, a 5 kg/m2 increase in BMI was strongly associated with oesophageal adenocarcinoma (RR 1.52, p<0.0001) and with thyroid (1.33, p=0.02), colon (1.24, p<0.0001), and renal (1.24, p <0.0001) cancers. In women, we recorded strong associations between a 5 kg/m2 increase in BMI and endometrial (1.59, p<0.0001), gallbladder (1.59, p=0.04), oesophageal adenocarcinoma (1.51, p<0.0001), and renal (1.34, p<0.0001) cancers. We noted weaker positive associations (RR <1.20) between increased BMI and rectal cancer and malignant melanoma in men; postmenopausal breast, pancreatic, thyroid, and colon cancers in women; and leukaemia, multiple myeloma, and non-Hodgkin lymphoma in both sexes. Associations were stronger in men than in women for colon (p<0.0001) cancer. Associations were generally similar in studies from North America, Europe and Australia, and the Asia-Pacific region, but we recorded stronger associations in Asia-Pacific populations between increased BMI and premenopausal (p=0.009) and postmenopausal (p=0.06) breast cancers.
Increased BMI is associated with increased risk of common and less common malignancies. For some cancer types, associations differ between sexes and populations of different ethnic origins. These epidemiological observations should inform the exploration of biological mechanisms that link obesity with cancer.
以体重指数（BMI）升高表示的超重与一些常见成人癌症的风险相关。我们进行了一项系统评价和荟萃分析，以评估BMI与不同癌症部位之间关联的强度，并调查这些关联在性别和种族群体之间的差异。
我们对Medline和Embase（1966年至2007年11月）进行了电子检索，并检索报告以识别20种癌症类型的发病病例的前瞻性研究。我们对研究特异性增量估计值进行随机效应荟萃分析和荟萃回归，以确定BMI每增加5kg/m²与癌症风险的关联。
我们分析了221个数据集（141篇文章），包括282,137例发病病例。在男性中，BMI每增加5kg/m²与食管腺癌（RR 1.52，p<0.0001）、甲状腺癌（1.33，p=0.02）、结肠癌（1.24，p<0.0001）和肾癌（1.24，p<0.0001）密切相关。在女性中，我们记录到BMI每增加5kg/m²与子宫内膜癌（1.59，p<0.0001）、胆囊癌（1.59，p=0.04）、食管腺癌（1.51，p<0.0001）和肾癌（1.34，p<0.0001）密切相关。我们注意到BMI升高与男性直肠癌和恶性黑色素瘤、女性绝经后乳腺癌、胰腺癌、甲状腺癌和结肠癌，以及两性白血病、多发性骨髓瘤和非霍奇金淋巴瘤之间存在较弱的正相关（RR<1.20）。结肠癌的关联在男性中比女性更强（p<0.0001）。北美、欧洲、澳大利亚和亚太地区的研究中的关联通常相似，但我们记录到亚太人群中BMI升高与绝经前（p=0.009）和绝经后（p=0.06）乳腺癌之间的关联更强。
BMI升高与常见和罕见恶性肿瘤风险增加相关。对于某些癌症类型，关联在性别和不同种族人群之间存在差异。这些流行病学观察结果应为探索将肥胖与癌症联系起来的生物学机制提供依据。
