Clinical outcome of maximum androgen blockade using flutamide as second-line hormonal therapy for hormone-refractory prostate cancer.
OBJECTIVE
To investigate the efficacy of maximum androgen blockade (MAB) using flutamide as second-line hormonal therapy for advanced hormone-refractory prostate cancer (HRPC).


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Miyake
Hideaki
H
Department of Urology, Hyogo Medical Center for Adults, Akashi, Japan. hideakimiyake@hotmail.com
Hara
Isao
I
Eto
Hiroshi
H
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D000813:Anilides / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005485:Flutamide / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles; D009919:Orchiectomy / Q000379:methods; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000601:surgery; D016019:Survival Analysis; D014105:Tosyl Compounds; D016896:Treatment Outcome
D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014105:Tosyl Compounds; D005485:Flutamide; C053541:bicalutamide; D017430:Prostate-Specific Antigen