RATIONALE: Androgens can cause the growth of prostate cancer cells. Hormone therapy using drugs, such as leuprolide, goserelin, flutamide, or bicalutamide, may fight prostate cancer by lowering the amount of androgens the body makes. Radiation therapy uses high-energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as docetaxel and prednisone, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. It is not yet known whether giving hormone therapy and radiation therapy together with chemotherapy is more effective than giving hormone therapy together with radiation therapy in treating prostate cancer.