KINGSTON, Jamaica - Researchers from the University of Southern California have uncovered a link between marijuana use and the risk of developing forms of testicular cancer that carry a somewhat worse prognosis.

The findings were published in on online magazine named 'Cancer'. 

The researchers suggest that the "potential cancer-causing effects of marijuana on testicular cells should be considered not only in personal decisions regarding recreational drug use, but also when marijuana and its derivatives are used for therapeutic purposes in young male patients".

Victoria Cortessis, assistant professor of preventive medicine at University of Southern California (USC), and colleagues looked at the self-reported history of recreational drug use in 163 young men diagnosed with testicular cancer and compared it with that of 292 healthy men of the same age and race/ethnicity.

The investigators found that men with a history of using marijuana were twice as likely to have subtypes of testicular cancer called non-seminoma and mixed germ cell tumors. These tumors usually occur in younger men and carry a somewhat worse prognosis than the seminoma subtype.

"We do not know what marijuana triggers in the testes 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," said Cortessis.

“If this is correct, then ‘prevention’ would come at a high price, although germ cells can not develop cancer if they are first destroyed, fertility would also be impaired. Since this is the first study in which an association between cocaine use and lower testis cancer risk is noted, additional epidemiological studies are needed to validate the results,” she said.