Study: Smoking marijuana may double risk of testicular cancer

According to a U.S. study released today, smoking marijuana may increase a male's risk of developing testicular cancer by as much as 70 per cent compared to those who don't smoke pot. The Seattle-area study included 369 men ages 18 to 44 who had testicular cancer and 979 men of the same age bracket who didn't. The results showed the risk of getting testicular cancer was highest among men who said they smoked pot for at least 10 years, more than once a week, starting before the age of 18. The study also showed those who smoke marijuana are 70 per cent more likely to develop testicular cancer compared to those who do not smoke marijuana. "Our study is not the first to suggest that some aspect of a man's lifestyle or environment is a risk factor for testicular cancer, but it is the first that has looked at marijuana use," said author Stephen M. Schwartz, M.P.H., Ph.D., an epidemiologist and member of the Public Health Sciences Division at the Hutchinson Center. The results appear in the journal Cancer. The study showed an increased risk in nonseminoma testicular cancer which accounts for 40 per cent of testicular cancer cases. Doctors told Reuters this form of testicular cancer can be aggressive and difficult to treat. Dr. Janet Daling, another one of the study's authors, told the BBC that puberty might be a "window of opportunity" during which boys were more vulnerable to environmental factors such as the chemicals in marijuana. The causes of testicular cancer are still relatively unknown. It often strikes men in their 20s and 30s and it responds well to treatment. The American Cancer Society says the disease has a five-year survival rate of about 96 per cent after treatment. The group also says about 8,000 American men are diagnosed with testicular cancer every year and about 140,000 men are alive today after surviving the disease. Henry Scowcroft from Cancer Research UK told the BBC statistical conclusions cannot be drawn yet, as the researchers only interviewed a relatively small number of men for this study. The authors of the study also say more research is needed.