Low doses of oral dexamethasone for hormone-refractory prostate carcinoma

BACKGROUND. Although glucocorticoids have been used to treat patients with hormone-refractory prostate carcinoma (HRPC), reports have varied regarding the types and doses of glucocorticoids used as well as their clinical benefits. In the current study, low doses of dexamethasone were investigated for their specific beneficial effects and the feasibility of long term treatment. METHODS. Thirty-seven patients diagnosed with HRPC were treated with oral dexamethasone (0.5-2 mg/day). The patients ranged in age from 53-89 years (median, 74 years]. Thirty-two patients, including 6 with lymph node metastases, had bone involvement whereas only 5 patients were found to have elevated serum prostate specific antigen (PSA) levels. RESULTS. Twenty-three patients (62%) who received no other concomitant therapy demonstrated a decline in their serum PSA level of greater than or equal to 50%, which was confirmed by a second PSA value obtained greater than or equal to 4 weeks later. The median time to PSA progression was 9 months. Among 18 patients with bone pain, 11 (61%) had improvement and in 5 patients (28%) the pain became stable. Among 21 patients with interpretable bone scans, 4 (19%) showed improvement and 8; (38%) achieved stable disease. Both symptomatic and objective responses of bone metastases were correlated with declines in the serum PSA level of greater than or equal to 50%. Ten patients achieved an increase in their hemoglobin level of at least 2 g/dL. Patients whose PSA level declined by greater than or equal to 50% with therapy had significantly prolonged survival (median, 22 months). As pretreatment markers, a longer interval before the initial evidence of-disease progression appeared was found to correlate significantly with posttherapy PSA declines of greater than or equal to 75%. All side effects of the glucocorticoids were reported to be mild. CONCLUSIONS. Low doses of dexamethasone were found to be beneficial in the treatment of HRPC, decreasing the severity of anemia and osseous disease as well as reducing serum PSA levels. A posttherapy serum PSA decline of greater than or equal to 50% appears to be a reliable marker of improved survival with this therapy. Cancer 2000;89: 2570-6.. (C) 2000 American Cancer Society.