The Two Beans Worth Coffee Blog at espressocoffeesnobs.com references an LA Times article as stating:

In a study done by Rutgers University, NJ, the scientists found that rats could reduce the likelihood of pre-cancerous sun-damaged cells from becoming cancerous by 100% if the rats either exercised or drank caffeine. However, when both the exercise and caffeine were combined, the preventative qualities of the combo raised the efficacy to a whopping 400%

I found the actual study report at rutgers.edu.
I’ll drink caffeine to that (oh and run to that when I can).