Recent studies show that survival for men with prostate cancer that has spread to the bone is just under two years. But this form of cancer, though aggressive, can sometimes be controlled. Here's what oncologists who treat prostate cancer say are the most common strategies for treating a cancer like Biden's, and some of the challenges.

Guidelines advise no screening after age 70, and doctors say that even men who test diligently may develop an aggressive cancer after none was found at a recent checkup.