Clinical efficacy of alternative antiandrogen therapy in Japanese men with relapsed prostate cancer after first-line hormonal therapy.
BACKGROUND
To confirm the effectiveness of alternative antiandrogen therapy (AAT) in Japanese patients with prostate cancer relapse after first-line hormonal therapy.


METHODS
A total of 80 patients who had successive serum prostate-specific antigen (PSA) progression after first-line hormonal therapy (luteinizing hormone-releasing hormone agonist alone: 21 cases; combined antiandrogen blockade therapy: 59 cases) were enrolled. We evaluated the positive ratio of antiandrogen withdrawal syndrome (AWS), the PSA responses with second- and third-line AAT, and cause-specific survival in terms of the effectiveness of AAT.


RESULTS
The overall positive AWS ratio after first-line therapy was 33%, while that after second-line therapy was 7%. There was no correlation between the first-line PSA response and the positive AWS. Of the 10 positive and the 20 negative AWS cases, secondary antiandrogen administration was effective in 50% and 60% of cases, respectively. The positive PSA responders at second- and third-line therapy were 51% and 13%, respectively. For second-line therapy, the effective rates from steroidal to non-steroidal, from non-steroidal to non-steroidal antiandrogen, and from non-steroidal to steroidal were 83%, 43%, and 14%, respectively. The cause-specific survival of the second-line responders was significantly better than that of the non-responders.


CONCLUSIONS
There was a substantial number of patients who found second-line AAT to be modestly effective. Flutamide was effective as an alternative antiandrogen for the patients' relapse treatment with bicalutamide in Japanese men.
Okihara
Koji
K
Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan. okihara@koto.kpu-m.ac.jp
Ukimura
Osamu
O
Kanemitsu
Noriyuki
N
Mizutani
Yoichi
Y
Kawauchi
Akihiro
A
Miki
Tsuneharu
T
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy*; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D015996:Survival Rate; D017211:Treatment Failure
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D007987:Gonadotropin-Releasing Hormone