There's some recent medical research about the use of capsaicin in cancer treatment. Those links lead to abstracts of the American Association of Cancer Research (AACR) discussing the effects. But you might have to be a real chilihead to have benefit: they used capsaicin in tests with mice and other animals. To slow down the growth and minimize the size of a prostatic cancer a 100 kg man would (calculatively) have to eat 400 mg capsaicin or 36 Mexican pepper pods (not precised) at least three days a week...
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT
http://www.aacrmeetingabstracts.org...INDEX=0&sortspec=relevance&resourcetype=HWCIT