It was a study done on mice, and it had nothing to do with ingestion of capsaicin: "These results might imply that caution should be exercised when using capsaicin-containing topical applications in the presence of a tumor promoter, such as, for example, sunlight."

The wikipedia article on capsaicin links to this study as well as several others and indicates that capsaicin may have carcinogenic or anticarcinogenic properties based on several studies: http://en.wikipedia.org/wiki/Capsaicin#Effects_of_dietary_co...

You probably shouldn't be all that concerned about eating spicy food... on the other hand, if you don't smoke, you eat well, and you aren't obese, you're roughly 55-65% less likely to die of cancer: http://en.wikipedia.org/wiki/Cancer#Causes