March 31st, 2009

Regular Marijuana Use May Increase Risk of Testicular Cancer


Men who frequently smoke marijuana may have an increased risk of developing nonseminoma testicular cancer, according to the results of a study published in Cancer.1

The testicles are located inside the scrotum (a sac of loose skin that lies directly under the penis). Testicular cancer—also called germ cell cancer—occurs in the tissues of one or both testicles. Testicular cancers are relatively rare but highly curable and occur predominantly in young and middle-aged males. The incidence of testicular cancer has been increasing in many western countries. Between 1975 and 2002, the rate of testicular cancer doubled in the United States. Testicular cancer is broadly divided into two different types, seminoma and nonseminoma, based on the appearance of cells under the microscope. Nonseminomas are, in general, more difficult to cure than seminomas.

The cause of testicular cancer is poorly understood. Developed countries have a higher prevalence of the disease than undeveloped countries, which suggests that environmental factors may be involved. An increased incidence of testicular cancer has been associated with early puberty, testicular trauma, cigarette smoking, exposure to toxic substances such as lead, and now, marijuana smoking.

Researchers from the Fred Hutchinson Cancer Research Center in Seattle conducted a population-based, case-control study of 369 men ages 18-44 who were diagnosed with testicular cancer between 1999 and 2006 and were from three counties in Washington. They interviewed the men and then compared their responses with those of 979 age-matched controls from the same three counties.

The results indicated that 26% of the men with testicular cancer were marijuana smokers compared with 20% of the men without testicular cancer. The researchers observed a 70% increased risk among current marijuana smokers. They note that the risk was further elevated for weekly use and use that began in adolescence. Furthermore, marijuana use appeared to increase the risk of nonseminoma cancers but not seminomas.

The researchers concluded that they observed an association between marijuana use and nonseminoma testicular cancer, but also acknowledge that their study had limitations. Much more research will need to be conducted before a direct link can be established. In the meantime marijuana users simply need to note that their habit may put them at an increased risk of developing testicular cancer.


1 Daling JR, Doody DR, Sun X, et al. Association of marijuana use and the incidence of testicular germ cell tumors. Cancer. 2009; 115:1215-1223.

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Tags: Testicular Cancer, Uncategorized