A modified low-dose regimen of mitoxantrone and prednisolone in patients with androgen-independent prostate cancer

Background: We conducted this retrospective study to analyze a modified dose schedule of mitoxantrone and prednisolone (MP) in patients with androgen-independent prostate cancer. Methods: From June 1997 to April 2002, 28 patients were enrolled. Their median age was 69 years (range, 58-79 years). The median duration of hormonal therapy was 30 months (range, 6-84 months). The median performance status was 2. Sixteen of the patients had bone disease only. The chemotherapy consisted of 8 mg/m² mitoxantrone by intravenous infusion every 3 weeks and 10 mg prednisolone orally twice per day. WHO response criteria, prostatic-specific antigen (PSA), pain and performance status were used to assess the response. Results: The median number of treatment cycles was six (range, 2-20). Nine (32.1%) and 15 patients (53.8%) had ≥80% and ≥50% reduction in serum PSA level, respectively. Of 16 patients using narcotics, five (31.3%) had a ≥50% reduction in narcotics consumption compared with the baseline. Nine patients (32.1%) showed improved performance. For 12 patients with measurable disease, only two (16.7%) showed a partial response. Grade 3-4 toxicities included neutropenia (three patients), anemia (three patients) and vomiting (one patient). The median survival was 12 months and the median time to PSA progression was 4 months. Conclusions: This modified regimen is feasible for palliative intent. The toxicity of this regimen is manageable. Exploring further combinations of this regimen with novel agents against androgen-independent prostate cancer is warranted.