For some patients with prostate cancer, the best choice may be expectant therapy. Expectant therapy also is called “watchful waiting.” Expectant therapy may be recommended if a cancer is not causing any symptoms and is expected to grow very slowly. This approach is particularly suited for men who are elderly or have other serious health problems. Because prostate cancer often spreads very slowly, many older men who have the disease may never require treatment. Some other men choose watchful waiting because the side effects of other treatments outweigh their benefit. Expectant therapy does not mean that a man receives no medical care. Rather, his cancer is regularly and carefully monitored with PSA and clinical evaluation. Active treatment can be instituted when disease progression is seen.