Smoking that joint doubles the risk for testicular cancer

New study is the third in recent years associating marijuana smoking and testicular cancer

In a population based control study researchers examined the relationship between testicular germ cell tumors (TGCT) and exposure to marijuana and other recreational drugs and found smoking marijuana had almost twice the risk for TGCT in comparison to those who never smoked marijuana.

For this new study researchers from Keck School of Medicine at the University of Southern California compared 163 patients that were diagnosed with TGCT in Los Angeles County from December 1986 to April 1991 and 292 healthy participants that were matched on age, race and neighborhood for the control group. Participants self-reported history of recreational drug use.

Researchers adjusted for history of tumor, education, religion and range of recreational drugs that included LSD, marijuana, cocaine, barbiturates and methamphetamine.

Overall the results had shown in comparison to those who never used drugs those who used marijuana (current or former) had a two-fold increased risk for two types of testicular cancer; nonseminoma and mixed germ cell tumors.

The research also revealed that those who had used cocaine had about half the risk of developing testicular cancer in comparison to those who did not use the drug. However, cocaine does not provide benefits for the testicles.

In an animal study from Wayne State University School of Medicine showed that cocaine resulted in prolonged vasoconstriction of the blood vessels to the testes.

The authors conclude “A specific association was observed between marijuana use and the risk of nonseminoma and mixed tumors.”

Dr. Victoria Cortessis, MSPH, PhD, assistant professor of preventive medicine at the Keck School of Medicine, stated "We do not know what marijuana triggers in the testis that may lead to carcinogenesis, although we speculate that it may be acting through the endocannabinoid system -- the cellular network that responds to the active ingredient in marijuana -- since this system has been shown to be important in the formation of sperm," as reported by Science Daily.

In conclusion researchers write “The current results warrant mechanistic studies of marijuana's effect on the endocannabinoid system and TGCT risk and caution that recreational and therapeutic use of cannabinoids by young men may confer malignant potential to testicular germ cells.”

This study appears online in Cancer.

Past research from Fred Hutchinson Cancer Research Center had found that frequent and/or long term marijuana may significantly almost double the risk of developing the most aggressive type of testicular cancer.

Dr. Stephen M. Schwartz, M.P.H., Ph.D., an epidemiologist and member of the Public Health Sciences Division at the Hutchinson Center, author of study, had stated "Our study is the first inkling that marijuana use may be associated with testicular cancer, and we still have a lot of unanswered questions.”

"What young men should know is that first, we know very little about the long-term health consequences of marijuana smoking, especially heavy marijuana smoking; and second, our study provides some evidence that testicular cancer could be one adverse consequence.”

The study had appeared on line February 9, 2009, in the journal Cancer.

More information on the health effects of marijuana can be viewed at Brown University Health Education.