Phase II trial of oral uracil/tegafur plus leucovorin in patients with hormone-refractory prostate carcinoma

Efficacy of tegafur-uracil (UFT) administration in castration-resistant prostate cancer patients with a history of both alternative antiandrogen therapy and estramustine phosphate sodium hydrate therapy

PURPOSE

The purpose of this study was to evaluate the efficacy of tegafur-uracil (UFT) administration as a fourth-line therapy in patients with castration-resistant prostate cancer (CRPC) who had already received combined androgen blockade (CAB) therapy (first-line), alternative antiandrogen therapy (second-line), and estramustine phosphate sodium hydrate (EMP) therapy (third-line), in order to determine who would benefit from UFT therapy.

METHODS

UFT was administered at a daily dose of 300 mg/m(2) to 26 patients, and the response to UFT 4 weeks after its induction and its toxicity were evaluated.

RESULTS

A reduction in the serum prostate-specific antigen (PSA) value was observed in 12 patients (46.2 %), while two cases (7.7 %) achieved more than 50 % reduction in PSA. Two patients (7.7 %) required discontinuation of UFT administration because of side effects (grade 2 exanthema in one patient and grade 2 nausea in one patient). A PSA response to UFT was observed, especially in patients older than 75 years and/or whose Gleason score was 8 or less.

CONCLUSIONS

Our data indicate that UFT administration as a fourth-line therapy was tolerable and effective to some degree in patients with CRPC who had already received CAB therapy, alternative antiandrogen therapy, and EMP therapy. It can be used, even in patients aged more than 75 years old, without any loss of efficacy or effect on their activities of daily life, and can be regarded as a treatment option for patients with advanced prostate cancer.

Pemetrexed as second-line chemotherapy for castration-resistant prostate cancer after docetaxel failure: results from a phase II study

OBJECTIVE

Although there is no standard treatment after docetaxel failure in patients with castration-resistant prostate cancer (CRPC), second-line chemotherapy is increasingly required. Its mechanism of action and toxicity profile make pemetrexed suitable for testing in this setting.

METHODS AND MATERIALS

Patients with docetaxel-resistant CRPC received pemetrexed 500 mg/m(2) every 3 weeks for 6 courses. The usual premedication with vitamin supplementation and dexamethasone prophylaxis was regularly administered. The primary objective was to quantify the biochemical response rate.

RESULTS

The biochemical response rate was 10.5% (95% CI 1.3-33.1), with 2 patients showing a reduction in prostate specific antigen (PSA) of ≥50%. The null hypothesis that the PSA response rate would be less than 20% was therefore accepted, and patient accrual was stopped after the evaluation of the 19th patient. The 1-year overall survival rate was 61.5%, with a median survival of 14 months. A considerable proportion of the patients (36%) were withdrawn from the study because of hematologic and nonhematologic toxicity.

CONCLUSIONS

Our experience with pemetrexed in CRPC patients appears discouraging in terms of activity and toxicity. No further studies of this drug should be performed in CRPC patients.

Quantitative analysis of the enzymes associated with 5-fluorouracil metabolism in prostate cancer biopsies

Orotate phosphoribosyl transferase (OPRT) is the initial enzyme of 5-FU activation, in which 5-FU is converted to 5-fluorouridinemonophosphate. Dihydropyrimidine dehydrogenase (DPD) is a degrading enzyme that catabolizes 5-FU. In this study, we investigated the expression of these enzymes in normal prostate gland (NP), hormone-sensitive prostate cancer (HSPC), and hormone-refractory prostate cancer (HRPC). The prostatic tissue specimens were obtained from patients who had undergone prostate needle biopsies without any treatments or with PSA failure after initial androgen deprivation. The tissue samples derived from formalin-fixed, paraffin-embedded (FFPE) sections were prepared by laser-capture microdissection, and from them RNA was extracted. The levels of OPRT and DPD mRNA expression were examined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The level of OPRT mRNA expression in the HSPC or the HRPC specimens was significantly higher than that in the NP specimens. There was a significant correlation between OPRT mRNA expression levels and the tumor pathological grade. Furthermore, the OPRT/ DPD expression ratio, a powerful predictive factor to evaluate 5-FU sensitivity, in the HRPC group was significantly higher than that in the low-grade HSPC group. Thus, the quantitative evaluation for these enzymes based on phosphorylation of 5-FU may be an effective option for some prostate cancer patients, particularly HRPC group.