No association between lung cancer and cannabis smoking in large studyA large study on the association between cannabis smoking and lung cancer already presented at the 2005 Meeting of the International Cannabinoid Research Society was now also presented at The American Thoracic Society Conference in San Diego and received much media interest. The study with 611 lung cancer patients and 1,040 healthy controls as well as 601 patients with cancer in the head or neck region found no increased risk for lung cancer even after heavy long-term use of cannabis.
"We expected that we would find that a history of heavy marijuana use - more than 500 to 1,000 uses - would increase the risk of cancer from several years to decades after exposure to marijuana," lead researcher Dr. Donald Tashkin of the University of California, Los Angeles, said in the Scientific American. But the scientists found that even those who smoked more than 20,000 cannabis cigarettes in their life did not have an increased risk of lung cancer.
(Sources: Scientific American of 24 May 2006; Morgenstern H, et al. Marijuana use and cancers of the lung and upper aerodigestive tract: results of a case-control study. Presentation at the ICRS Conference on Cannabinoids, 24-27 June 2005, Clearwater, USA)
Source: No Association Between Lung Cancer And Cannabis Smoking In Large Study