Study suggests increased testicular cancer risk with marijuana use

Dianne St. Jean

November is also known as “Movember”, the month for awareness of male diseases, including and especially prostrate and testicular cancer.

The focus of Movember has been on support and fundraising for those suffering from the diseases, as well as to raise awareness of their growing prevalence and necessity for early detection.

However, apart from an apparent association with male cancer risk and ethnic or family background, there has been little discussion as to other potential contributors to the development of male cancers.

Now, research results from Sweden have found a possible link between heavy use of marijuana and the development of testicular cancer.

The longitudinal study by Dr. Russ Callaghan and an international team of researchers from Karolinska University (Sweden) and the Division of Cancer Epidemiology and Genetics at the National Cancer Institute in the U.S, examined data from young men conscripted for military service in Sweden in 1969 and 1970, and then tracked their health conditions over the following 40+ years. (A longitudinal study involves repeated observations of the same variables [e.g., people] over long periods of time, sometimes over decades).

The study, as well as three other prior case-control studies in this area, suggests that cannabis use may facilitate later onset of testicular cancer, with as much as a two and a half-fold increased risk of developing the cancer with heavy use.

“At this time, surprisingly little is known about the impacts of cannabis on the development of cancer in humans,” said Dr. Callaghan, the study’s lead author.

The study was published this month in the journal Cancer Epidemiology, Biomarkers & Prevention:

According to Dr. Callaghan, the potential health risks of regular cannabis use should be a consideration in light of proposed cannabis legalization.

“With Canada and other countries currently experimenting with the decriminalization or legalization of recreational cannabis use, it is critically important to understand the potential harms of this type of substance use.

 “Our study is the first longitudinal study showing that cannabis use, as measured in late adolescence, is significantly associated with the subsequent development of testicular cancer. My hope is that these findings will help medical professionals, public health officials and cannabis users to more accurately assess the possible risks and benefits of cannabis use.”