Filho, AdalbertoTurner, Michelle C.Warnakulasuriya, SamanRichardson, David B.Hosseini, BayanKamangar, FarinPourshams, AkramSewram, VikashCronin-Fenton, DeirdreEtemadi, ArashGlass, Deborah C.Rahimi-Movaghar, AfarinSheikh, MahdiMalekzadeh, RezaSchubauer-Berigan, Mary K.2023-03-272023-03-272023M Filho A, Turner MC, Warnakulasuriya S, Richardson DB, Hosseini B, Kamangar F, Pourshams A, Sewram V, Cronin-Fenton D, Etemadi A, Glass DC, Rahimi-Movaghar A, Sheikh M, Malekzadeh R, Schubauer-Berigan MK. The carcinogenicity of opium consumption: a systematic review and meta-analysis. Eur J Epidemiol. 2023 Apr;38(4):373-89. DOI: 10.1007/s10654-023-00969-70393-2990http://hdl.handle.net/10230/56359The carcinogenicity of opium consumption was recently evaluated by a Working Group convened by the International Agency for Research on Cancer (IARC). We supplement the recent IARC evaluation by conducting an extended systematic review as well as a quantitative meta-analytic assessment of the role of opium consumption and risk for selected cancers, evaluating in detail various aspects of study quality on meta-analytic findings. We searched the published literature to identify all relevant studies on opium consumption and risk of selected cancers in humans through 31 October, 2022. Meta-relative risks (mRRs) and associated 95% confidence intervals (CIs) were estimated using random-effects models for studies of cancer of the urinary bladder, larynx, lung, oesophagus, pancreas, and stomach. Heterogeneity among studies was assessed using the I2 statistic. We assessed study quality and conducted sensitivity analyses to evaluate the impact of potential reverse causation, protopathic bias, selection bias, information bias, and confounding. In total, 2 prospective cohort studies and 33 case-control studies were included. The overall pooled mRR estimated for 'ever or regular' versus 'never' use of opium ranged from 1.50 (95% CI 1.13-1.99, I2 = 0%, 6 studies) for oesophageal cancer to 7.97 (95% CI 4.79-13.3, I2 = 62%, 7 studies) for laryngeal cancer. Analyses of cumulative opium exposure suggested greater risk of cancer associated with higher opium consumption. Findings were robust in sensitivity analyses excluding studies prone to potential methodological sources of biases and confounding. Findings support an adverse association between opium consumption and cancers of the urinary bladder, larynx, lung, oesophagus, pancreas and stomach.application/pdfeng© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1007/s10654-023-00969-7CancerCase-control studyCohort studyMeta-analysisOpiuminfo:eu-repo/semantics/openAccess