Afshari Mahdi, Janbabaei Ghasem, Bahrami Mohammad Amin, Moosazadeh Mahmood
Department of Community Medicine, Zabol University of Medical Sciences, Zabol, Iran.
Gastrointestinal Cancer Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
PLoS One. 2017 Jun 6;12(6):e0178527. doi: 10.1371/journal.pone.0178527. eCollection 2017.
The association between opium use and bladder cancer has been investigated in many studies, with varying reporting results reported. This study aims to estimate the total odds ratio for the association between bladder cancer and opium consumption using meta-analysis.
The study was designed according to PRISMA guidelines. Two independent researchers searched for the relevant studies using PubMed, Web of Science, Scopus, OVID, Embase, and Google Scholar. After systematic screening of the studies identified during the first step, Cochrane risk of bias tool was determined for the selected studies. The case-control and the cohort studies were investigated to assess risk of bladder cancer due to opium use. In addition, the cross-sectional studies were analysed separately to assess frequency of opium consumption. These estimates were combined using the inverse variance method. Fixed or random effect models were applied to combine the point odds ratios. The heterogeneity between the primary results was assessed using the Cochran test and I-square index. The suspected factors for heterogeneity were investigated using meta-regression models. An Egger test was conducted to identify any probable publication bias. Forest plots illustrated the point and pooled estimates. All analyses were performed using Stata version 14 software and RevMan version 5.3.
We included 17 primary studies (11 case-control, one cohort and five cross-sectional) in the final meta-analysis. The total odds ratios (95% confidence intervals) for developing bladder cancer by opium use alone, and concurrent use of opium and cigarettes were estimated as 3.85 (3.05-4.87) and 5.7 (1.9-16.3) respectively. The odds ratio (95% confidence interval) for opium use with or without cigarette smoking was estimated as 5.3 (3.6-7.7).
This meta-analysis showed that opium use similar to cigarette smoking and maybe with similar mechanisms can be a risk factor for bladder cancer. It is therefore expected to be a risk factor for other cancers.
许多研究对鸦片使用与膀胱癌之间的关联进行了调查，报告结果各不相同。本研究旨在通过荟萃分析估计膀胱癌与鸦片消费之间关联的总比值比。
本研究按照PRISMA指南设计。两名独立研究人员使用PubMed、科学网、Scopus、OVID、Embase和谷歌学术搜索相关研究。在对第一步确定的研究进行系统筛选后，为所选研究确定了Cochrane偏倚风险工具。对病例对照研究和队列研究进行调查，以评估因使用鸦片导致膀胱癌的风险。此外，对横断面研究进行单独分析，以评估鸦片消费频率。使用逆方差法合并这些估计值。应用固定效应或随机效应模型合并点比值比。使用Cochran检验和I²指数评估主要结果之间的异质性。使用元回归模型研究异质性的可疑因素。进行Egger检验以识别任何可能的发表偏倚。森林图展示了点估计值和合并估计值。所有分析均使用Stata 14版软件和RevMan 5.3版软件进行。
我们在最终的荟萃分析中纳入了17项主要研究（11项病例对照研究、1项队列研究和5项横断面研究）。仅使用鸦片以及同时使用鸦片和香烟导致患膀胱癌的总比值比（95%置信区间）分别估计为3.85（3.05 - 4.87）和5.7（1.9 - 16.3）。无论是否吸烟，使用鸦片的比值比（95%置信区间）估计为5.3（3.6 - 7.7）。
这项荟萃分析表明，与吸烟类似且可能具有相似机制的鸦片使用可能是膀胱癌的一个危险因素。因此，预计它也是其他癌症的危险因素。
