Weekly paclitaxel and high-dose 5-fluorouracil plus leucovorin in hormone-refractory prostate cancer: in vitro combined effects and a phase II trial.
OBJECTIVE
Paclitaxel and 5-fluorouracil have been used to treat hormone-refractory prostate cancer with some success. In vitro data suggest that the combined cytotoxicity may be sequence dependent. Thus, we explored the combined effects of the 2 agents, both in vitro and in vivo.


METHODS
The combined cytotoxicity of paclitaxel and 5-fluorouracil, and the possible schedule dependence were studied in vitro using PC-3 and DU145 cells and the microculture tetrazolium assay. There were 23 patients with hormone-refractory prostate cancer treated with the regimen T-HDFL: paclitaxel 90 mg/m2 intravenously 1 hour on days 1 and 8; 5-fluorouracil 2000 mg/m2; and leucovorin 300 mg/m2 intravenous 24-hour infusion on days 2 and 9, which repeated every 21 days. The allowed percentage of bone marrow irradiation was 50%.


RESULTS
Significant synergistic cytotoxicity was seen only when paclitaxel was given 24 hours before 5-fluorouracil. With the T-HDFL regimen, 11 (52%) of the 21 evaluable patients had > or = 50% reduction of prostate-specific antigen, lasting for 6 weeks. Of the 7 patients with measurable disease, 2 had a partial response. Median overall survival was 14.1 months. Grade III/IV leukopenia occurred in 2 patients. There was no treatment-related death. Toxicities were well tolerated.


CONCLUSIONS
The combined cytotoxicity of paclitaxel and 5-fluorouracil is schedule dependent. It is feasible to administer weekly paclitaxel and high-dose 5-fluorouracil infusions in patients with hormone-refractory prostate cancer. Our findings may serve as an important rationale for future trial design.
Lin
Chia-Chi
CC
Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan.
Hsu
Chih-Hung
CH
Hour
Tzyh-Chyuan
TC
Cheng
Ann-Lii
AL
Huang
Chao-Yuan
CY
Huang
Kuo-How
KH
Chen
Jun
J
Pu
Yeong-Shiau
YS
D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D004334:Drug Administration Schedule; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy; D017239:Paclitaxel / Q000008:administration & dosage / Q000009:adverse effects; D011471:Prostatic Neoplasms / Q000188:drug therapy*
D017239:Paclitaxel; D002955:Leucovorin; D005472:Fluorouracil