Effect of estrogen therapy on metastatic carcinoma of the prostate.

Forty-one patients with metastatic carcinoma of the prostate (stage IV) were treated with diethylstilbestrol or bilateral orchidectomy or both and followed for a period of two years. The effect of treatment was determined every six months and was based on the size and consistency of the primary lesions on rectal palpation, the effects on pain, obstructive symptoms, osseous metastases, level of serum prostatic acid phosphatase and on the overall clinical evaluation of the patient. Bilateral orchidectomy was as effective as a combination of bilateral orchidectomy and diethylstilbestrol therapy. Diethylstilbestrol given alone was less effective. The poorer results obtained were attributed to the failure of many patients to adhere strictly to their estrogen regimen. Rectal digital palpation of the prostate as well as an estimation of the level of serum prostatic acid phosphatase is recommended in developing countries for all male patients over 50 years of age seen at the hospital.