A 42-year-old lawyer makes an appointment to see his family physician. His father (age 67) has just been diagnosed with metastatic prostate cancer. The patient has no significant medical history and has not seen a doctor since he had a vasectomy 7 years ago. He is an admitted junk-food addict, has a sedentary life-style and is moderately overweight. Palpation reveals no abnormalities of the prostate. The patient asks the physician's advice about reducing his risk of prostate cancer.