Opium Use and the Risk of Liver Cancer: A Case–Control Study

Abstract

Limited evidence is available to acknowledge the association between opium use and liver cancer. In a case–control study, we recruited 117 cases of primary liver cancer (PLC) and 234 age and sex-matched neighborhood controls from 2016 to 2018. We calculated odds ratios (OR) for opium use and 95% confidence intervals (95% CI), using conditional logistic regressions. Compared with non-users the adjusted OR (AOR, 95% CI) for opium use was 6.5 (95% CI, 2.87–13.44). Compared with people who had no history of use, a strong dose–response effect of opium use was observed by amount of use (AOR, 10.70; 95% CI, 3.92–28.70). Cumulative use of opium also indicated that using over 30 gr-year could increase the PLC risk dramatically (AOR, 11.0; 95% CI, 3.83–31.58). Those who used opium for more than 21 years were highly at risk of PLC (AOR, 11.66; 95% CI, 4.43–30.67). The observed associations were significant even among never tobacco smokers (including cigarette and water-pipe smoking). Prevention Relevance: The results of this study indicate that opium use dramatically increased the risk of liver cancer. Because opioids are increasing for medical and non-medical use globally; accordingly, severe health consequences such as liver cancer have to be investigated widely.