Carcinoma of the prostate:Treatment with external radiotherapy

Abstract

In recent years external radiotherapy has been selected as primary treatment of patients with carcinoma of the prostate localized to the pelvis. Among 146 patients treated with external radiotherapy at Columbia-Presbyterian Medical Center, the 5 and 10 year survival rates were 64.1% and 40.5%, respectively. The 5-year survival rate was 88.2% for patients with Stage A, 86.8% for Stage B and 58% for Stage C; it was 64.4% for patients with more differentiated carcinomas, but only 28.7% for patients with undifferentiated tumors. Patients with obstructive changes on IVP had a 5 year survival rate of 24.1%, whereas, for patients with no obstruction on IVP, this rate was 71.3%. When radiotherapy started within 6 months after the diagnosis, the 5 year survival rate was 70.3%, whereas, a delay in starting radiotherapy, for more than 6 months after the diagnosis, was associated with a survival rate of 31.9%. Radiation dose of 6500 rad or more was associated with a 5-year survival rate of 86.7%, whereas, for a dose of less than 6500 rad this survival rate was 57.1%. All the above differences were statistically significant (p < 0.05). Other factors that were examined and were found to influence the prognosis to a degree that was not statistically significant included: age of the patient at the time of radiotherapy, presenting symptoms, levels of acid phosphatase in the serum and in the bone marrow and size of the irradiated volume. In agreement with other published series the complications were usually mild and their incidence low. Tumor involving and protruding into the urethra may have contributed to the formation of urethral strictures. Local control of this cancer with external radiotherapy appears very successful. Treatment failures were manifested most often with distant metastases with or without local recurrence, suggesting that subclinical distant metastases might have been present prior to initiation of radiotherapy. External radiotherapy rather than brachyterhapy, appears to be the treatment of choice for cancer of the prostate with indications for radiotherapy.