RADIATION-THERAPY FOR PROSTATE-CANCER - LONG-TERM RESULTS AND IMPLICATIONS FOR FUTURE ADVANCES

Background. There are surprisingly few studies that concurrently report the 10-year overall survival (OS) rate, 10-year adjusted survival (AS) rate, 10-year recurrence free (NED) survival rate, and 10-year local tumor control (LC) rate using external beam radiation therapy (RT) for Stages A2, B, and C prostate cancer. A simultaneous analysis of OS, AS, NED survival, and LC rates is useful in terms of establishing priorities for future research efforts. Methods. Actuarial LC, NED survival, AS, and OS rates were analyzed for 289 patients with Stages A2, B, and C prostate cancer treated with RT between 1975 and 1990 in the Department of Therapeutic Radiology, Yale University School of Medicine. Results. The 10-year LC, NED survival, AS, and OS rates for 168 patients with Stage A2 and B disease were 88% (standard error [SE], 5%), 50% (SE, 10%), 70% (SE, 7%), and 38% (SE, 7%), respectively. The 10-year LC, NED survival, AS, and OS rates for 121 patients with Stage C disease were 82% (SE, 6%), 41% (SE, 6%), 25% (SE, 7%), and 21% (SE, 6%), respectively. Conclusion. External beam radiation provides excellent local clinical tumor control for early prostate cancer. However, 60% of all prostate cancer deaths of patients with Stage A2 and B disease and 76% of all prostate cancer deaths of patients with Stage C disease were attributable to metastatic disease without clinical local failure. The major obstacle in improving the death rate associated with Stages A2, B, and C prostate cancer remains the inability to control metastatic disease; research efforts must concentrate on overcoming this problem.