I believe that was ONE study that said masturbation could cause cancer (and even that study hardly could point to masturbation/ejaculation as the reason for the rise in cancer). You do not need to be afraid that you are doing something bad. I mean if you personally don't like masturbation, that's alright. But you aren't doing anything bad and I seriously doubt it would be a major contributing factor to cancer. Honestly, considering that most people masturbate (whether they admit it or not), seems like everyone would have cancer if that were even remotely accurate. Its perfectly natural to masturbate and nothing to feel so much remorse and shame over.