Clinical outcome of maximum androgen blockade using flutamide as second-line hormonal therapy for hormone-refractory prostate cancer.
ABSTRACT To investigate the efficacy of maximum androgen blockade (MAB) using flutamide as second-line hormonal therapy for advanced hormone-refractory prostate cancer (HRPC).
The study included 55 patients with HRPC who were treated with MAB using flutamide (375 mg daily) as second-line hormonal therapy. All patients had previously received bicalutamide combined with either surgical or medical castration as first-line hormonal therapy, which failed. The effect of the second-line therapy was evaluated by serum prostate-specific antigen (PSA) level alone, and the response defined as a decrease of >50% from the baseline PSA at the start of second-line therapy.
On initiating second-line hormonal therapy there was a reduction in the PSA level in 25 of the 55 patients (45%), among whom 12 (22%) were regarded as responders, while the PSA level continued to increase in the remaining 30 (55%). The median (range) duration of the PSA response was 6 (1-13) months. During the observation period there were no severe side-effects from the second-line MAB therapy. Patients without bone metastases or whose disease progressed >1 year after first-line therapy had a significantly higher incidence of PSA response to second-line therapy, despite no significant effect of other factors examined on the PSA response to second-line therapy. Furthermore, the cause-specific survival in responders to second-line therapy was significantly better than that in nonresponders; however, multivariate analysis showed that no factors, including response to second-line therapy, could be used as independent predictors of cause-specific survival.
MAB using flutamide as second-line hormonal therapy can give a comparatively favourable PSA response with no severe side-effects; therefore, this therapy may be suitable for patients with HRPC after primary MAB using bicalutamide has failed, particularly in those with no bone metastases or whose disease has progressed for >1 year after first-line therapy.
Article: Efficacy of alternative antiandrogen therapy for prostate cancer that relapsed after initial maximum androgen blockade.[show abstract] [hide abstract]
ABSTRACT: We evaluated the effectiveness of second-line maximum androgen blockade (MAB) with an alternative antiandrogen in patients who relapsed after initial MAB. We retrospectively analyzed 47 patients with prostate cancer who relapsed after initial MAB, including surgical or medical castration combined with antiandrogens, from January 1998 to December 2009. When the serum prostate-specific antigen (PSA) level was increased on three consecutive occasions, we discontinued the antiandrogen and then administered an alternative antiandrogen. Seven patients were assessed for antiandrogen withdrawal syndrome (AWS). The effect of the second-line MAB was evaluated by the serum PSA level, and response was subdivided into ≥50% and <50% PSA reductions from the baseline PSA at the start of second-line MAB. PSA reduction was observed in 32 patients (68.1%). Among them, 23 (48.9%) achieved ≥50% PSA reductions with a mean response duration of 13.4±5.4 months. Nine (19.2%) patients reached <50% PSA reductions with a mean response duration of 12.2±6.2 months. The time to nadir PSA level after first-line MAB in the ≥50% PSA reduction group, <50% PSA reduction group, and PSA elevation group was 15.6±12.9 months, 11.8±6.0 months, and 8±6.5 months, respectively. That is to say, it was significantly longer in the responder groups (p=0.038). Second-line MAB using an alternative antiandrogen is an effective treatment option before cytotoxic chemotherapy in patients who relapse after initial MAB.Korean journal of urology 07/2011; 52(7):461-5.