Smoking marijuana (cannabis) does not increase risk of head, neck cancer

Smoking marijuana (cannabis) does not increase the user's risk of head and neck cancer, according to a new study published in the March 2008 issue of Otolaryngology – Head and Neck Surgery.

The small sample study, authored by researchers from New Zealand and Great Britain, found that among 75 cases of head and neck cancer, the relative risk of smoking cannabis and contracting head and neck cancer in marijuana users was the same (1.0) as in those who had never smoked cannabis. These results differ from the relative risk of contracting cancer from smoking cigarettes (2.1) and the heavy consumption of alcohol (5.7), compared with those who abstained from those activities.

However, due to the limits of the study, the authors cannot exclude other possible effects, and recommend a larger study.

Cancers of the head and neck, with more than 500,000 new cases diagnosed each year worldwide, represent the fourth most common type of cancer. It is estimated that more than 13,000 people will die from head and next cancer each year in the United States alone.