Metabolic and radioactive tracer studies in carcinoma of the prostate: Effect of diethylstilbestrol and of orchiectomy

Abstract

1. 1. Sixteen patients with bone metastases secondary to carcinoma of the prostate and one patient without bone metastases were studied under controlled dietary conditions. Metabolic balance studies of calcium, phosphorus and nitrogen, calcium tolerance tests and radioisotope studies were performed. 2. 2. A marked tendency to calcium retention was noted in patients with osteoblastic metastases. The urinary excretion of calcium of untreated patients frequently was extremely low. Even in the active stage of bone disease, the calciuria was rarely as high as in patients with bone involvement caused by other tumors. The calcium balance of six untreated patients was normal on low calcium intake and was negative in one patient. Calcium retention, as indicated by the calcium tolerance test, was greater than normal in a large number of patients. 3. 3. The urinary excretion of radiocalcium and radiostrontium was extremely low in some patients. The magnitude of the tracer excretions depended on the state of the calcium metabolism of the patient. 4. 4. Estrogen therapy resulted in a decrease in urinary excretion of calcium and improvement of the calcium balances. Hormone-induced changes of calcium metabolism were paralleled by changes in Ca 45 excretion. The retention of infused calcium increased further during estrogen therapy. There was a good correlation between the changes in calcium metabolism induced by estrogen and the clinical response. An increase in calcium retention as estimated by the calcium tolerance test may be a better objective indicator of the effectiveness of therapy than the decrease in urinary excretion of calcium. 5. 5. The urinary excretion of calcium of six patients, in whom orchiectomy was performed at varying time intervals prior to the balance studies, was either in the normal range or extremely low. The calcium balances were normal on a low calcium intake. The calcium balance of one patient was negative due to high urinary excretion of calcium. 6. 6. Balance studies performed in two patients before and after orchiectomy revealed marked nitrogen retention following this procedure. The urinary excretion of calcium of one of these patients decreased to half the control excretion.