Scientists from the University of Southern California's Keck School of Medicine published a study today that linked the recreational use of Marijuana to increased risk of testicular cancer.
Their research was published in CANCER, a peer reviewed journal of the American Cancer Society.
Researchers examined the self-reported drug-use data 163 young men who had testicular cancer, comparing that information with 292 healthy and demographically similar men.
They found those "with a history of using marijuana were twice as likely to have subtypes of testicular cancer called non-seminoma and mixed germ cell tumors." Those kinds of tumors, researchers said, had a "worse prognosis than the seminoma subtype."
One website notes the connection between marijuana use and testicular cancer has been made before. CANCER previously published two studies that reported similar findings.
Researcher Victoria Cortessis, MSPH, Ph.D., said in a statement more research was still required.
"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."
The study concluded:
"A specific association was observed between marijuana use and the risk of nonseminoma and mixed tumors. To the authors' knowledge, this is the first report of a negative association between cocaine use and TGCT [Testicular germ cell tumor] risk. 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."
Translation: You may want to put down that joint.