U.S. researchers for the first time have found a link between a surge in marijuana use and increased incidence of testicular cancer. Although the association between cannabis use and the disease is limited to the aggressive nonseminoma types of testicular cancer (which develops earlier than other types and generally affects men between 20 and 35), the study revealed a shocking 70 per cent increased risk for regular long-term cannabis users. Research for the study was conducted at at the Fred Hutchinson Cancer Research Center in Seattle, where 369 men in their twenties and thirties with testicular cancer were asked about their history of marijuana use. Their responses were compared with those from just under 1,000 men without the disease from a similar age group. Even after factors like smoking, family history, and drinking habits were considered—marijuana use was revealed to be a significant possible cause in the study, published in the journal Cancer. Despite the findings, the researchers warn that the results are not definitive, but they suggest that marijuana may disrupt the working of a chemical in the body which is thought to have a protective effect against cancer.