IARC Volume 126 | Opium consumption
Lyon, France, 9 October 2020 – The International Agency for Research on Cancer (IARC), the cancer
agency of the World Health Organization (WHO), has evaluated the carcinogenicity of opium
A Working Group of 16 international experts was convened by the IARC Monographs programme for a
meeting, which was held remotely. After thoroughly reviewing the available scientific literature, the
Working Group classified opium consumption as carcinogenic to humans (Group 1).
A summary of the final evaluations has now been published online in The Lancet Oncology. The detailed
assessments will be published as Volume 126 of the IARC Monographs.
Results of the evaluation
There was sufficient evidence for the carcinogenicity of opium consumption in humans. Opium
consumption causes cancers of the larynx, lung, and urinary bladder. There was also strong mechanistic
evidence in experimental systems that opium in the form of sukhteh (opium dross, the tarry residues
formed after smoking raw opium) and opium pyrolysates (solid residues of combusted opium) exhibits key
characteristics of carcinogens. There was inadequate evidence in experimental animals regarding the
carcinogenicity of opium consumption.
The Group 1 classification applies to both ingestion and smoking as routes of exposure and to all forms of
minimally processed opium that are consumed (e.g. raw opium, opium dross, and opium sap). It does not
apply to other opiates (e.g. heroine , morphine, and codeine) or opioids (e.g. fentanyl).
A summary of the evaluations has now been published in The Lancet Oncology: article; pdf.
Read the Q&A
View the infographic
Read the press release
CONTINUE READING ON monographs.iarc.fr