While the medical use of marijuana continues to be debated, a new study has found a link between recreational use of cannabis and an increased risk of developing of testicular cancer.
Researchers at the University of Southern California looked at 163 young men diagnosed with testicular cancer who used marijuana and compared them with 292 healthy men of the same age and ethnicity who did not use marijuana.
What they found was 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 types of tumors are usually found in younger men and carry a somewhat worse prognosis than the seminoma subtype.
“We do not know what marijuana triggers in the testis that may lead to carcinogenesis,” said Victoria Cortessis, PhD, one of the study’s authors and an assistant professor of preventive medicine at USC’s Keck School of Medicine. “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.”
The study’s findings appear to support those from two previous reports in CANCER, a peer reviewed journal of the American Cancer Society, on a potential link between marijuana use and testicular cancer. But some have criticized those previous reports as flawed, because they rely on a small sampling of men with testicular cancer and because their use of marijuana was self-reported on a questionnaire.
The authors of the most recent study noted that there was a likelihood that some of the men with testicular cancer were reluctant to report a history of recreational drug use, and that could impact the results.
Nonetheless, they say the findings suggests that the potential cancer causing effects of cannabis on testicular cells should be considered not only in personal decisions regarding recreational marijuana use, but also when marijuana and its derivatives are used for therapeutic purposes in young male patients.
Researchers also discovered that men with a history of using cocaine had a reduced risk of both subtypes of testicular cancer. Though the exact reason is unclear, they suspect it has to do with the cocaine’s tendency to kill sperm producing cells in research animals.
“If this is correct, then ‘prevention’ would come at a high price,” Cortessis said. She added that although germ cells cannot 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.
Testicular cancer is the most common cancer diagnosed in young men ages 15 to 45 years. The malignancy is becoming more common, and researchers suspect this is due to increasing exposure to unrecognized environmental causes.
One of the most publicized battles with testicular cancer was that of bicyclist Lance Armstrong. He was diagnosed in 1996 after he began feeling a lower energy level, started coughing blood, and had a painful testicle. He was found to have testicular cancer that had spread throughout his body to his lungs and brain.
After nearly a year of treatment, Armstrong was cancer free.