Ouch!  That’s not a nice association.

This was a story I couldn’t exactly pass up, because it’s a such a high-interest topic.  But, the scientists involved, and every bit of training I’ve had, warn me not to make too much of it.  (Check out the story that aired on KPLU for an overview, and here’s a press release.)

Steve Schwartz of the Fred Hutchinson Cancer Research Center has been trying to understand what causes testicular cancer.  You don’t hear much about testicular cancer (unless there’s a story about cyclist Lance Armstrong) because it’s uncommon and it’s usually curable.  But, it’s also poorly understood.  At the urging of his colleague, Janet Daling, they decided to ask if there’s any association between testicular cancer and marijuana smoking.

Based on a survey of men in the Seattle area, some with cancer, some without, they found marijuana smokers had a slightly higher risk of getting testicular cancer.  It’s newsworthy because it’s the first time anyone has shown any sort of link between marijuana and an elevated cancer risk.  The study has several limitations, so it really just points to a possibility, and the need to do more careful studies.  In general, Schwartz points out, our knowledge of the long-term effects of marijuana smoking is small.

Here are some interesting tidbits from Schwartz and the study:

• The more often you smoke pot, the more your risk goes up.  Maybe the marijuana functions as some sort of “fuel” to keep the cancer cells growing.  When you stop, their growth stops, too.  This pattern has been shown in some types of breast and lung cancer.
• Testicular cancer is also associated with height.  Taller men, especially those over 6 ft. 2 in., have higher rates than shorter men.
• Men of African descent don’t tend to get testicular cancer.

It’s a cancer that seems to be triggered in adolescence, and mostly hits men between the ages of 15 and 35.

Add up that profile:  Young, white, tall man who smokes pot.  Seen any of these on a college campus?

(The paper is in the journal Cancer, and it’s called “Association of Marijuana Use and the Incidence of Testicular Germ Cell Tumors.”)