Association between opium use and bladder cancer: A case-control study in a high risk area of Iran

Is opium use related to the increased risk of oral cavity cancers? A case-control study in Iran

BACKGROUND

Oral cavity cancers (OCCs) are the sixth most prevalent cancers in the world. There are strong evidences showing the risk of the cigarette smoking, alcohol use, poor oral hygiene and some types of diets in OCCs; however, few studies explored the relationship between opium and its derivatives (O&D) use and OCCs incidence. The aim of this study was to investigate the relationship between consumption of O&D and the incidence of OCCs.

METHODS

In a case-control; 133 patients with OCCs and 266 healthy controls matched by age, sex, and place of residence were included. Data, including cigarette smoking, O&D, alcohol and others tobacco (Nass, pipe and hookah) use and diet, were collected using a structured questionnaire. The relation between the use of O&D and OCCs was evaluated using conditional logistic regression.

RESULTS

Opium ever-use was associated with an increased risk of OCCs (Adjusted Odds Ratio (AOR) =2.36, 95 % CI: 1.16-4.78). A dose-response relation was observed between the amount of daily O&D use and OCCs; and the relation was stronger in high users (AOR for low users = 1.38, 95 %CI: 0.58-3.24 and AOR for high users = 4.85, 95 % CI:1.79-13.11). Those who used opium for more than 18 years were highly at risk of OCCs (AOR= 5.04, 95 % CI, 2.00-12.68). Also, OCCs was higher among subjects starting the use of O&D at younger ages (≤ 50 years old vs never users AOR = 3.32, 95 % CI: 1.19-9.23). The smoking method of consuming O&D increased the odds of getting OCCs more than twice (AOR= 2.02, 95 % CI, 1.03-3.94), and using both smoking and oral consumption simultaneously, increased the odds of getting OCCs more than 8 times (AOR= 8.57, 95 % CI, 1.68-43.70). Also, the use of other tobacco products (Nass, pipe and hookah) increases the odds of getting OCCs by 4 times (AOR= 3.90, 95 % CI, 1.12-13.57) CONCLUSIONS: The results showed that opium use is probably a dose related risk factor for oral cavity cancers. Therefore, it is necessary to implement preventive policies to control the use of opioids.

The carcinogenicity of opium consumption: a systematic review and meta-analysis

The 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.

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

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.

Opium use and risk of bladder cancer: a multi-centre case-referent study in Iran

BACKGROUND

Bladder cancer (BC) is the 10th most common type of cancer worldwide and the fourth most common type of cancer in Iran. Opium use is considered as one of the risk factors for BC. We aim to assess the association between various parameters of opium use, which in Iran is mainly ingested or smoked in various forms, and the risk of BC.

METHOD

In this multi-centre case-referent study in Iran, 717 BC cases and 3477 referents were recruited to the study from May 2017 until July 2020. Detailed histories of opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure adjusted odds ratio (OR) and 95% confidence intervals (CI). The ORs were adjusted for age, gender, place of residence and pack-years of cigarette smoking.

RESULTS

Regular opium consumption was associated with an increased risk of BC (OR 3.5, 95% CI: 2.8, 4.3) compared with subjects who never used opium. Compared with continuous users, the risk decreased to one-third for those who stopped opium more than 10 years ago. The adjusted OR for those who used both crude opium (teriak) and opium juice was 7.4 (95% CI: 4.1, 13.3). There was a joint effect of opium and tobacco (OR for users of both opium and tobacco 7.7, 95% CI: 6.0, 9.7).

CONCLUSIONS

Regular opium use is associated with an approximately 4-fold risk for BC. The OR decreases along with the increasing time since stopping opium use.