Marijuana and cancer

The Abramson Cancer Center of the University of Pennsylvania
Last Modified: May 8, 2013

Share article


Question

I am wondering if any cases of lung cancer (or other cancer) can result from smoking marijuana?

Answer

Barbara Campling, MD, Medical Oncologist, responds:

Yes, there is evidence that marijuana smoking can cause cancer, in particular lung cancer. Smoke from burning marijuana contains many of the same carcinogens found in tobacco smoke, some in even higher concentrations. It has been difficult to sort out the contribution of marijuana to lung cancer, since many marijuana smokers also use tobacco. Furthermore, it may be difficult to obtain accurate information about the use of illicit drugs. Here are a number of studies that you may want to look up:

  1. Barsky SH, et al. Histopathologic and molecular alterations in bronchial epithelium in habitual smokers of marijuana, cocaine, and/or tobacco. Journal of the National Cancer Institute 90: 1198-1205 (1998). This group found premalignant changes in the airways of smokers of marijuana or crack cocaine that were very similar to the changes found in tobacco smokers. These changes were not detected in the airways of non-smokers.
  2. Mao L, et al. Does marijuana or crack cocaine cause cancer? Journal of the National Cancer Institute 90: 1182-1184 (1998). This paper reviews the evidence for an association between marijuana use and lung cancer, as well as head and neck cancer.
  3. Fung M, et al. Lung and aero-digestive cancers in young marijuana smokers. Tumori 85: 140-142 (1999). This is a report from the Department of Radiation Oncology at the University of Pennsylvania of a number of young patients with lung or other aero-digestive cancers who were marijuana users.


News
Study Finds Smoking Marijuana Not Linked to Risk of COPD

Nov 23, 2014 - Though smoking only marijuana wasn't linked to higher risk of chronic obstructive pulmonary disease, smoking tobacco or both marijuana and tobacco was associated with higher risk, according to research published in the April 14 issue of CMAJ, the journal of the Canadian Medical Association.



I Wish You Knew

What is Photodynamic Therapy and how is it used in cancer care?

View More



Blogs and Web Chats

OncoLink Blogs give our readers a chance to react to and comment on key cancer news topics and provides a forum for OncoLink Experts and readers to share opinions and learn from each other.




OncoLink OncoPilot

Facing a new cancer diagnosis or changing the course of your current treatment? Let our cancer nurses help you through!

Learn More