High dose bicalutamide for androgen independent prostate cancer: effect of prior hormonal therapy.
OBJECTIVE
A pilot study of the antiandrogen bicalutamide at 150 mg. a day for androgen independent prostate cancer was performed. This study was based on the possibility that androgen independent cases might display responses to additional hormonal agents.


METHODS
The study included 31 androgen independent cases with an increasing prostate specific antigen (PSA) and progressive disease. PSA measurements were used as the primary method of assessing response. However, PSA decline was also correlated with clinical status.


RESULTS
Seven patients demonstrated PSA declines of greater than 50% for 2 months or more, for an overall response rate of 22.5%. Responses were observed almost exclusively in patients treated with long-term flutamide as part of a complete androgen blockade regimen (43% response rate) in contrast to patients treated with androgen deprivation without flutamide (6% response rate). Of the 7 PSA responding patients bicalutamide resulted in a significant improvement in performance status and a decrease in analgesic requirement in 4 and 3 remained asymptomatic. Bicalutamide at 150 mg. a day was well tolerated, with the most frequent side effect being mild exacerbation of hot flashes.


CONCLUSIONS
Bicalutamide at this dose is modestly effective for some patients with androgen independent prostate cancer, particularly for those previously treated with long-term flutamide. This study indicates that previous antiandrogen therapy alters the response to subsequent hormonal agents.
Joyce
R
R
Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
Fenton
M A
MA
Rode
P
P
Constantine
M
M
Gaynes
L
L
Kolvenbag
G
G
DeWolf
W
W
Balk
S
S
Taplin
M E
ME
Bubley
G J
GJ
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D000813:Anilides / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D005485:Flutamide / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles; D010865:Pilot Projects; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy*; D014105:Tosyl Compounds
D000726:Androgen Antagonists; D000813:Anilides; D000970:Antineoplastic Agents; D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014105:Tosyl Compounds; D005485:Flutamide; C053541:bicalutamide; D017430:Prostate-Specific Antigen