By Paul Armentano, NORML Deputy Director
Marijuana smoke exposure is not positively associated with the development of cancers of the head or neck, according to the results of a systematic literature review published online ahead of print in the journal Archives of Oral Biology.
Investigators from the Federal University of Minas Gerais in Brazil reviewed nine case-control studies to assess whether marijuana smoking favored the development of head and neck cancer. Authors reported that subjects who used cannabis were no more likely to develop the disease than were subjects with no history of use, after researchers controlled for potential confounding such as age, gender, race, and the use of tobacco and alcohol.
"The result of this study indicated no association between lifetime marijuana use and the risk for development of head and neck cancer," authors concluded.
A separate analysis of six case-control studies published last year in the International Journal of Cancer similarly identified no positive association between cannabis smoke exposure and lung cancer, while a 2009 case-control trial published in the journal Cancer Prevention Researchreported that the moderate levels of marijuana use were associated with a reduced risk of head and neck cancer.