SMOKING MARIJUANA LINKED TO INCREASED RISK OF TESTICULAR CANCER

Researchers at the University of Southern California (USC) have linked recreational marijuana use to an increased risk of developing testicular germ-cell tumors, the most frequent tumor type in men aged 15 to 45. The study results were published in the journal Cancer, a journal of the American Cancer Society.

The increase in risk for marijuana users was approximately twofold. The current study confirms two previous studies published in Cancer demonstrating a potential link between smoking marijuana and testicular cancer. The same study also found that men who used cocaine had a twofold reduction in risk of testicular cancer.

“The risk of testicular germ-cell tumors has been rising for decades, but exposures responsible for the increases have not been identified,” said Victoria Cortessis, MSPH, PhD, one of the authors of the study.

“A reason to suspect marijuana in particular,” explained Cortessis, “is that constituents of marijuana smoke have been shown to perturb hormone levels, and hormonal factors have been implicated in testis cancer etiology for some time.” Aside from the potential that marijuana smoke contains testicular carcinogens, previous population-based studies have suggested that those with testicular cancer were more likely to have smoked marijuana.

The results could have implications for providing marijuana and its derivatives as therapy for younger male patients.

Testicular cancer, specifically, testicular germ-cell tumors, are the most common cancer type in men between the ages of 15 and 45. The cancer type is becoming more common. The culprits are believed to be environmental factors, most of which are still unknown. It is important to try to understand the mechanisms that may facilitate development of germ-cell tumors as men with testicular cancer, following treatment, remain at risk for secondary primary tumors as well as cardiovascular disease. An established risk factor is undescended testicles or cryptorchidism.

Currently, evidence points to abnormal steroid levels and effects during both perinatal and peripubertal development as a potential culprit. These abnormalities could stem from exposure to maternal estrogens(Drug information on estrogens) or environmental hormones during development, for example. Animal studies have found cryptorchidism to be associated with exposure to environmental estrogen exposure. Higher risk of testicular cancer is also linked to severe acne and male pattern baldness, suggesting a man’s varied hormone levels also may play a part.

By Anna Azvolinsky, PhD¹ | September 12, 2012

¹Freelance Science Writer and CancerNetwork