Background: We previously reported that weekly treatment with docetaxel alone is useful for and well tolerated by patients with hormone-refractory prostate cancer (HRPC). Here, we compare it with the regimen of docetaxel once every 3 weeks (q3w) plus daily prednisone (PSL) based on a TAX 327 trial in order to clarify the efficacy and toxicity of docetaxel regimens in Japan.
Methods: Thirty-two patients with HRPC were treated with docetaxel weekly (regimen 1) or docetaxel q3w plus PSL daily (regimen 2) at Tsukuba University Hospital and the changes in serum prostate-specific antigen (PSA), tumor size and survival were evaluated. The dose of docetaxel in regimen 1 was based on our previous report and that of regimen 2 was modified from a TAX 327 trial.
Results: A >50% decrease in PSA was observed in 53% of the patients with a median time to progression of 3.5 months and 69% with 8.5 months with regimens 1 and 2, respectively. Patients who received regimen 2 had a significantly better survival rate than those who received regimen 1. Myelosuppression and neuropathy were statistically more frequent in regimen 2 than in regimen 1.
Conclusion: A regimen of docetaxel q3w with PSL daily was associated with a high rate of PSA reduction and prolongation of patient survival. Although docetaxel has not been approved in Japan yet, this treatment is considered feasible for Japanese patients with HRPC.