Study Links Marijuana Use to Testicular Cancer

Study Links Marijuana Use to Testicular Cancer

Study Links Marijuana Use to Testicular Cancer
Article date: September 12, 2012
By Stacy Simon
Researchers in California have found a possible link between using marijuana and developing
testicular cancer. Conducting a case-control study in Los Angeles County, they found that men who
had testicular germ cell tumors were about twice as likely to report having ever used marijuana as men
without these tumors.
Testicular cancer is expected to be diagnosed in 8,590 men in 2012. It is often highly treatable, and
usually curable. More than 90% of these cancers are germ cell tumors. The rate of testicular cancer
has been increasing for several decades, but experts are not sure why. The study, published online
Sept. 10, 2012 in the American Cancer Society journal Cancer, speculates that environmental causes,
including recreational drug use, may play a role.
In the study, 163 men diagnosed with testicular germ cell tumors and 292 men not diagnosed with the
tumors were interviewed about their recreational drug use. The researchers found that men with these
tumors were about twice as likely to have a history of using marijuana. Most of the increased risk was
found in men with a germ cell tumor sub-type called non-seminomas. This type of tumor is harder to
treat and usually occurs in men between their late teens and early 30s.
Case-control studies such as this compare a group of people with a certain disease to a group of
similar people without it, to look for factors that may contribute to the disease. However, this type of
study can’t prove that a factor actually causes the disease. Other types of studies are needed for this.
Study author Victoria K. Cortessis, MSPH, PhD, of the University of Southern California in Los
Angeles said her team based its hypothesis on research that shows the active ingredient in marijuana
may interfere with normal hormone signaling between the brain and the testicles. Cortessis and her
team plan to conduct research that will look at those processes.
Cortessis said, “Three studies have now found the same specific result – a history of marijuana use
associated with double the risk of non-seminoma testicular cancer. This is a more dangerous type of
testicular cancer that requires chemotherapy treatment. We have to take it seriously.”
The researchers also found that men with a history of cocaine use actually had a reduced risk of
testicular cancer. Cortessis speculates this might be because cocaine destroys testicular germ cells,
whether they are healthy or not. Destroying the cells prevents them from becoming cancerous, but
also leads to infertility because germ cells produce sperm.
Len Lichtenfeld, MD, deputy chief medical officer for the American Cancer Society cautioned that the
study’s findings are preliminary, and the number of men studied was small. Lichtenfeld said, “The
study is interesting, but the findings are not conclusive. More research needs to be done to form a
firmer conclusion that this is a definite relationship (between marijuana use and testicular cancer risk).”
Citation: Population-Based Case-Control Study of Recreational Drug Use and Testis Cancer Risk
Confirms an Association Between Marijuana Use and Nonseminoma Risk. Published online Sept. 10,
2012 in Cancer. First author: Victoria K. Cortessis MSPH, PhD, University of Southern California, Los
Angeles.
http://www.cancer.org/cancer/news/news/study-links-marijuana-use-to-testicular-cancer