Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.
Junior Research Group Systematic Reviews, Institute for Biometrics and Epidemiology, German Diabetes Center, Düsseldorf.
Ann Oncol. 2017 Jun 1;28(6):1217-1229. doi: 10.1093/annonc/mdx080.
Colorectal adenomas are known as precursors for the majority of colorectal carcinomas. While weight gain during adulthood has been identified as a risk factor for colorectal cancer, the association is less clear for colorectal adenomas. We conducted a systematic review and meta-analysis to quantify the evidence on this association.
We searched Medline up to September 2016 to identify observational (prospective, cross-sectional and retrospective) studies on weight gain during adulthood and colorectal adenoma occurrence and recurrence. We conducted meta-analysis on high weight gain versus stable weight, linear and non-linear dose-response meta-analyses to analyze the association. Summary odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using a random effects model.
For colorectal adenoma occurrence, the summary OR was 1.39 (95% CI: 1.17-1.65; I2: 43%, N = 9 studies, cases = 5507) comparing high (midpoint: 17.4 kg) versus stable weight gain during adulthood and with each 5 kg weight gain the odds increased by 7% (2%-11%; I2: 65%, N = 7 studies). Although there was indication of non-linearity (Pnon-linearity < 0.001) there was an increased odds of colorectal adenoma throughout the whole range of weight gain. Three studies were identified investigating the association between weight gain and colorectal adenoma recurrence and data were limited to draw firm conclusions.
Even a small amount of adult weight gain was related to a higher odds of colorectal adenoma occurrence. Our findings add to the benefits of weight control in adulthood regarding colorectal adenoma occurrence, which might be relevant for early prevention of colorectal cancer.
结直肠腺瘤被认为是大多数结直肠癌的前体。虽然成年人的体重增加已被确定为结直肠癌的危险因素，但与结直肠腺瘤的关系不太明确。我们进行了系统评价和荟萃分析，以量化这一关联的证据。
我们搜索了 Medline 数据库，截至 2016 年 9 月，以确定关于成年人期间体重增加与结直肠腺瘤发生和复发的观察性（前瞻性、横断面和回顾性）研究。我们对高体重增加与稳定体重、线性和非线性剂量反应荟萃分析进行了荟萃分析，以分析这种关联。使用随机效应模型估计汇总比值比（OR）和 95%置信区间（95%CI）。
对于结直肠腺瘤的发生，高体重增加（中点：17.4kg）与稳定体重增加相比，汇总 OR 为 1.39（95%CI：1.17-1.65；I2：43%，N=9 项研究，病例=5507），并且体重每增加 5kg，几率增加 7%（2%-11%；I2：65%，N=7 项研究）。尽管存在非线性的迹象（Pnon-linearity < 0.001），但在整个体重增加范围内，结直肠腺瘤的几率都有所增加。有 3 项研究调查了体重增加与结直肠腺瘤复发之间的关系，但数据有限，无法得出明确的结论。
即使是少量的成年人体重增加也与结直肠腺瘤发生的几率增加有关。我们的发现增加了成年人控制体重对结直肠腺瘤发生的益处，这可能与结直肠癌的早期预防有关。
