Oral etoposide and oral prednisone for the treatment of castration resistant prostate cancer

Treatment options for patients with castration-resistant prostate cancer (CRPC) are limited. The purpose of our study was to investigate the safety and efficacy in terms of prostate-specific antigen (PSA) response of a low-dose oral combination of etoposide and prednisone in patients with CRPC. Thirty-nine patients with prostate cancer (median age, 77.9 years) with progressive disease after standard hormonal therapy were enrolled. Etoposide (25 mg, twice daily) and prednisone (5 mg, twice daily) were administered orally. Each cycle comprised 21 consecutive days of treatment followed by a 7-day drug holiday. All patients previously treated with an antiandrogen were required to undergo antiandrogen withdrawal prior to entry into the study. A total of 226 cycles were administered with a median of 6.7 cycles per patient (range, 1–18 cycles). Sixteen of 39 patients (41%) with elevated PSA levels at baseline achieved at least a 50% reduction in PSA levels. Median progression-free survival for all patients was 5.9 months (range, 1–17 months). No Grade 4 toxicities were observed. The predominant toxicities were mucositis, nausea, fatigue, and anemia in twelve, nine, eight, and seven patients, respectively. Hematologic toxicity was infrequent, with no episodes of febrile neutropenia. The combination of low-dose etoposide and prednisone is an efficacious and reasonably well-tolerated oral regimen in the treatment of elderly patients with CRPC. This regimen can be easily administered in an outpatient setting and does not require frequent patient visits.