Lung cancer and cannabis. No association found in literature review, but precancerous changes shown in some
Posted: July 14, 2006 13:03
Arch Intern Med. 2006;166:1359-1367
The Association Between Marijuana Smoking and Lung Cancer: A Systematic Review.
Mehra R, Moore BA, Crothers K, Tetrault J, Fiellin DA.
Dear Readers,
Our attention is drawn to this week's Archives of Internal Medicine with its catchy, capitalized headline "The Association Between Marijuana Smoking and Lung Cancer". Despite the appearance of an assumed association, in fact the researchers published findings, after examining 19 rigorous studies, were that there was NO association between cannabis smoking and cancer. So why would the journal's editors imply in big letters that such an association exists?
The authors state: 'Observational studies of subjects with marijuana exposure failed to demonstrate significant associations between marijuana smoking and lung cancer after adjusting for tobacco use'. <snip> 'Therefore, we must conclude that no convincing evidence exists for an association between marijuana smoking and lung cancer based on existing data.'
Many of us believe that there probably is an association between any smoked organic product and lung damage. However, when 19 rigorous studies fail to show an association with cancer, we are entitled to conclude that the effect must be relatively small, and substantially less than the long accepted causation with tobacco. The authors' conclusions is that 'physicians should advise patients regarding potential adverse health outcomes' of cannabis.
It would appear that politics even pervades peer reviewed journals. Reefer madness is still with us! I note that the study and one of its authors were partially supported by the National Institute on Drug Abuse (NIDA) in America. This is the second 'difficulty' for Director Nora Volkow in a week (see magic mushroom story elsewhere).
Further evidence of the disconnect between science and drug policy is that even the most serious scientists and clinicians in America still often use the slang term 'marijuana' rather than the correct scientific (Latin) 'cannabis' or common English 'Indian hemp'.
Comment by Andrew Byrne ..
Mehra R, Moore BA, Crothers K, Tetrault J, Fiellin DA. The Association Between Marijuana Smoking and Lung Cancer: A Systematic Review. Arch Intern Med. 2006;166:1359-1367
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