Marijuana Smoking and Lung Cancer
A Systematic Review - The Association Between Marijuana Smoking and Lung Cancer

The Archives of Internal Medicine published a July 10, 2006 article, "The Association Between Marijuana Smoking and Lung Cancer," by Reena Mehra, MD, et al. (Vol. 166, pp. 1359-1367), which reviewed published research studies on adult marijuana smokers between 1966 and Oct. 2005, which stated:

"Our objective was to assess the impact of marijuana smoking on the development of pre-malignant lung changes and lung cancer."

The article noted both pros and cons in their research:


"Observational studies of subjects with marijuana exposure failed to demonstrate significant associations between marijuana smoking and lung cancer after adjusting for tobacco use. The primary methodologic deficiencies noted include selection bias, small sample size, limited generalizability, overall young participant age precluding sufficient lag time for lung cancer outcome identification, and lack of adjustment for tobacco smoking."


"Studies that examined lung cancer risk factors or premalignant changes in the lung found an association of marijuana smoking with increased tar exposure, alveolar macrophage tumoricidal dysfunction, increased oxidative stress, and bronchial mucosal histopathologic abnormalities compared with tobacco smokers or nonsmoking controls."

The article concluded:

"Conclusion: Given the prevalence of marijuana smoking and studies predominantly supporting biological plausibility of an association of marijuana smoking with lung cancer on the basis of molecular, cellular, and histopathologic findings, physicians should advise patients regarding potential adverse health outcomes until further rigorous studies are performed that permit definitive conclusions."
June 28, 2006 Archives of Internal Medicine

Related Link: "Does the regular smoking of marijuana cause lung cancer or in any way permanently injure the lungs?".