Opium and bladder cancer: A systematic review and meta-analysis of the odds ratios for opium use and the risk of bladder cancer.
Mahdi AfshariGhasem JanbabaeiMohammad Amin BahramiMahmood MoosazadehPublished in: PloS one (2017)
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.