A new study finds that young men who use marijuana have an increased risk of testicular cancer, according to ABC News. The men in the study who smoked marijuana were twice as likely to develop the most common form of the disease in men under age 35, compared with those who didn’t smoke marijuana.
The tumors of marijuana smokers tended to grow more quickly, and were more difficult to treat, the researchers found.
“Most men who get testicular cancer today survive, and that’s wonderful. But as a result of treatment, they may have problems with fertility or sexual function,” said lead author Victoria Cortessis of the University of Southern California’s Keck School of Medicine in Los Angeles.
“So we’re talking about the risk of developing the cancer in the first place as well as the subsequent effects of the cancer and its treatment.”
It is unclear how marijuana might increase the risk of testicular cancer. Cortessis said that the drug may disrupt how testosterone regulates testes development and function, in a way that makes the testes much more vulnerable to cancer.
The researchers found that men who used cocaine were less likely to develop testicular cancer. Cortessis said this finding might be due to cocaine’s toxic effects. “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 noted in a news release.
The study appears in the journal Cancer.