Opium use and subsequent incidence of cancer: results from the Golestan Cohort Study
- Study type
- Observational study
- Study name
- Golestan Cohort — opium
- Design
- Prospective population-based cohort study (north-eastern Iran)
- Sample size
- 50,045 people; 1833 cancer cases
- Source
- Lancet Glob Health · 2020
In plain words
In Iran, opium is sometimes thought to be "harmless" or even a remedy. This large study of 50 thousand people in Golestan showed that regular opium use raises the risk of several cancers, including cancers of the oesophagus (gullet), stomach, lung, bladder and larynx (voice box), and the more opium is used, the higher the risk. This link was seen even in people who did not smoke cigarettes.
Key results
Study population
50,045 people aged 40 to 75 years from north-eastern Iran (Golestan Cohort Study) with a median follow-up of 10 years.
Endpoints
Outcome: cancer incidence (overall and by site) in regular opium users compared with non-users.
Clinical significance and place in guidelines
In 2020 the International Agency for Research on Cancer (IARC) (Monograph No. 126) classified opium consumption as "carcinogenic to humans" (Group 1): with sufficient evidence for cancers of the larynx, lung and bladder and limited evidence for cancers of the oesophagus, stomach, pancreas and pharynx. For physicians in regions where opium use is common, asking about opium use is part of assessing the risk of upper gastrointestinal, lung and bladder cancers.
Limitations
The study is observational; opium use was self-reported by questionnaire (although validated in earlier studies); residual confounding is possible; the number of cases of some cancers was small.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.