He's another link about cancer:

http://www.aim.org/media_monitor/A36_0_2_0_C/

The latest evidence about the fraud known as "medical marijuana" comes from a study by a team headed by Dr. Sarah Nuttall at Queen Elizabeth Hospital in Birmingham, England. Epidemiological studies made during the past 30 years have found that marijuana causes lung damage and probably cancer. The new study took blood samples, measured lung function and tested non-smokers and smokers for antioxidant markers.