Yes, marijuana is carcinogenic, but not as much as cigarettes. It contributes slightly toward some cancers, but nowadays, it seems like everything contributes somewhat toward cancer. It is an inevitable truth we all will have to face at some point. When the statistic says there are no recorded deaths from marijuana, it is referring to the fact that no one has ODed and died because of marijuana AS A RESULT OF AN OVERDOSE. That's because you'd have to smoke a few pounds in one day to OD, and after an ounce or two, you'd pass out first.

Hope this helps,
Greg