a href="http://www.ccguide.org/news/shownewsarticle.php?articleid=15689">Large Study Finds No Link between Marijuana and Lung Cancer: Scientific America, September 2010

TABLE 2 Relative Risk of Death for Ever Users and Current Users of Marijuana, by Sex and Cause of Death: Kaiser Pemanente Medical Care Program Members (n = 65,171), Oakland and San Francisco, June 1979 through December 1985 - section of table regarding cancer (Neoplasms) as the cause of death:
MEN
Ever Users Relative Risk of Cancer Death
Full Model 0.78
Nonsmokers/ Occasional Drinkers 0.46
Current Users
Full Model 0.97
Nonsmokers/ Occasional Drinkers 0.75
WOMEN
Ever Users
Full Model 0.82
Nonsmokers/ Occasional Drinkers 0.70
Current Users
Full Model 0.86
Nonsmokers/ Occasional Drinkers 0.56

Here, numbers less than one for Relative Risk of Cancer Death represent a lower rate of fatal cancer among marijuana smokers in the large Kaiser Study from California. For example, women who are current marijuana smokers but did not smoke tobacco, were found to have only 56% of the risk of cancer death as compared to other women who were non-smokers of both tobacco and marijuana.

SO, YOU THOUGHT IT WAS THE TAR THAT CAUSED CANCER