Besides avoiding obvious cancer-causing agents, not much. In my case, it was a benign tumor (a hemangioma), that sprung a leak. The leak was what caused the pr

Besides avoiding obvious cancer-causing agents, not much. In my case, it was a benign tumor (a hemangioma), that sprung a leak. The leak was what caused the problem. Doctor said it had probably been in my brain, all my life. It just started bleeding, for some unknown reason.