According to the NIH, the supplement CoEnzyme Q10 may be effective in protecting against some types of cancer. They write:
--- Cancer. Research suggests that low coenzyme Q-10 levels are associated with an increased risk of skin cancer. Also, early research suggests that taking coenzyme Q-10 along with other antioxidants increases survival time by 40% in patients with terminal cancer.Since this supplement offers all kind of other benefits (it's a great anti oxident for one), my take is can't hurt to take it daily. It's expensive but then, protecting one's health might be worth it! :)