Opium use and risk of lung cancer: A multicenter case‐control study in Iran

Abstract

Opium use was recently classified as a human carcinogen for lung cancer by the International Agency for Research on Cancer. We conducted a large, multicenter case‐control study evaluating the association between opium use and the risk of lung cancer. We recruited 627 cases and 3477 controls from May 2017 to July 2020. We used unconditional logistic regression analyses to estimate the odds ratios (OR) and 95% confidence intervals (CI) and measured the association between opium use and the risk of lung cancer. The ORs were adjusted for the residential place, age, gender, socioeconomic status, cigarettes, and water pipe smoking. We found a 3.6‐fold risk of lung cancer for regular opium users compared to never users (95% CI: 2.9, 4.6). There was a strong dose‐response association between a cumulative count of opium use and lung cancer risk. The OR for regular opium use was higher for small cell carcinoma than in other histology (8.3, 95% CI: 4.8, 14.4). The OR of developing lung cancer among opium users was higher in females (7.4, 95% CI: 3.8, 14.5) than in males (3.3, 95% CI: 2.6, 4.2). The OR for users of both opium and tobacco was 13.4 (95% CI: 10.2, 17.7) compared to nonusers of anything. The risk of developing lung cancer is higher in regular opium users, and these results strengthen the conclusions on the carcinogenicity of opium. The association is stronger for small cell carcinoma cases than in other histology.

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

“…Several case–control (n = at least 9) studies also used the GCS questionnaire (GCSQ) [ 7 , 31 , 32 , 34 , 35 , 37 , 41 , 52 , 55 ]. A similarly detailed questionnaire was also used in the IROPICAN study [ 38 , 42 , 43 , 52 ]. Other case–control studies ascertained exposure information from telephone calls, face-to-face interviews, patient records or public demographic information and usually characterised exposure as ever/never opium use [ 5 , 17 , 19 , 22 – 24 , 33 , 46 , 47 , 49 – 51 , 53 ].…”

“…For cancer of the oesophagus, two case–control studies had higher quality exposure information [ 7 , 41 ]. Three of the four lung cancer case–control studies [ 33 , 34 , 42 ], two of the six laryngeal cancer case–control studies [ 32 , 52 ], and one of the three pancreatic cancer case–control studies [ 35 , 36 , 44 ] also had higher quality exposure information with cumulative exposure estimates. Some bladder cancer case–control studies relied on patient records and did not define a minimum exposure for ‘ regular ’ user (hence the estimate could be interpreted as for an ‘ ever ’ user).…”

“… Rashidian et al (2022) [ 42 ] did not provide cumulative exposure by low (≤ median) or high (> median) categories of cumulative exposure compared to never users Shakeri et al 2013 (median = 50 hookah-years) Shakeri et al 2016 (median = 34 nokhod-year) Masjedi et al 2013 (median = 36.5 nokhod/day) Naghibzadeh et al 2020 (median = 87.5 g-years) Abdolahinia et al 2021 (1800 g-year in lifetime) Sheikh et al 2020 (median = 21 nokhod-years) Rashidian et al 2022 (not provided) …”

“…Rashidian et al (2022) [ 42 ] did not provide cumulative exposure by low (≤ median) or high (> median) categories of cumulative exposure compared to never users…”

“…There were 2 prospective cohort studies and 33 case-control studies. There were a total of six new case-control studies identified following the Monographs meeting [30,35,38,[42][43][44]. A total of 15 studies examined the association between opium consumption and bladder cancer (1 cohort and 14 case-control), 7 for laryngeal cancer (1 cohort and 6 case-control), 6 for oesophageal cancer (1 cohort and 4 case-control, one publication [41] describes two separate studies, with different sets of cases and controls), 5 for stomach cancer (2 cohort and 3 case-control), 5 for lung cancer (1 cohort and 4 case-control), and 4 for pancreatic cancer (1 cohort and 3 case-control).…”