Excessive marijuana use carries a high risk of oral cancers

People who smoke a lot of marijuana may face more than four times the chance of developing oral cancer, new research suggests.

"Cannabis smoke contains many of the same carcinogenic compounds found in tobacco smoke, which have known damaging effects on the epithelial tissue lining the mouth," noted study senior author Raphael Cuomo, an associate professor of anesthesiology at UC San Diego School of Medicine.