A study conducted at The Department of Urology, Yokosuka Kyosai Hospital, Japan, evaluated the efficacy and safety of using a low-dose chemotherapy combination of docetaxel, estramustine and dexamethasone in men with castrate resistant prostate cancer (CRPC). The study enrolled sixty-nine with CRPC. Docetaxel dosage was downed to 25 mg/m2 on days 1 and 8 every 3 weeks, oral estramustine was administered at a dose of 280 mg twice daily on days 1 to 3 and 8 to 10, and oral dexamethasone, 1mg daily throughout the protocol.
Cycles were repeated every 21 days and were continued until the men demonstrated disease progression or excessive toxicity. All subject men were evaluated for PSA response and toxicity. The subjects received a median of eleven cycles (range : 1-25). Prostatic-specific antigen (PSA) was decreased greater than 50% in 53 (77%) out of 69 men and median duration of PSA response was 10.2 months. Median time to progression and overall survival 10.2 and 24 months, respectively. Grade 1-2 fatigue was the most common toxicity observed in 10 (15%) patients. Grade 3-4 toxicities were observed in five (7%) patients (2 thrombosis, 2 bilirubin elevation, and 1 aspartate transaminase/alanine transaminase elevation).
The study has concluded that low-dose docetaxel, estramustine and dexamethasone when given in combination can be an effective chemotherapy protocol and is well tolerated for Japanese CRPC men.
There is no reason to believe that non-Japanese men would respond any differently, however, an additional study using a more diverse population would validate these results and demonstrate that this low dose chemotherapy protocol would also work in non-Japanese men with CRPC.
Reference: Hinyokika Kiyo. 2010 Apr;56(4):203-7.
Kobayashi K, Yokonishi T, Ito Y, Matsumoto T, Umemoto S, Osaka K, Nakamura M, Onuki T, Komiya A, Ohgo Y, Sakai N, Noguchi S, Kishi H, Yokomizo Y, Kawai M, Okajima K, Tajiri T, Fujikawa A, Ohta J, Yumura Y, Moriyama M.
Joel T Nowak, MA, MSW