Prostate-specific antigen half-life and pretreatment prostate-specific antigen: crucial predictors for prostate-specific antigen trend in delayed-combined androgen blockade therapy.
OBJECTIVE
To elucidate the crucial predictors for prostate-specific antigen (PSA) trends and determine the usage of anti-androgen treatment during delayed-combined androgen blockade (CAB) leading to a PSA level below 0.2 ng/mL.


METHODS
From January 2001 to December 2004, 105 prostate cancer patients were enrolled. Medical castration and anti-androgen treatment were used sequentially and termed delayed-CAB. The first goal was to maintain an undetectable PSA level. The nadir PSA was determined after medical castration only. Anti-androgen was given if a PSA level of more than 0.2 ng/mL was observed and the subsequent PSA response was assessed. All cases were divided into two groups based on whether the PSA was lower (n = 59) or higher (n = 46) than 0.2 ng/mL. An analysis of the difference between the two groups was calculated.


RESULTS
The median of the initial PSA level in the lower group was lower than in the higher group with a 95% cut-off level of 40 ng/mL. The median PSA half-life in the lower group was also reduced with a 95% cut-off of 3.6 months. In a multivariate analysis, the pretreatment PSA level and the PSA half-life exhibited a significant correlation between the two groups. Anti-androgen treatment was given to 26 cases in the higher group. The PSA increased in one case, decreased to less than 0.2 ng/mL in 17 cases and remained over 0.2 ng/mL in eight cases.


CONCLUSIONS
Both the PSA half-life and the pretreatment PSA level were useful markers for predicting the PSA trends to determine the optimal use of anti-androgen treatment during delayed-CAB.
Soga
Norihito
N
Division of Nephro-Urologic Surgery and Andrology, Department of Reparative and Regenerative Medicine, Institute of Medical Life Science, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan. uroclin@clin.medic.mie-u.ac.jp
Onishi
Takehisa
T
Arima
Kiminobu
K
Sugimura
Yoshiki
Y
D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; 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*; D014408:Biomarkers, Tumor / Q000097:blood; D004359:Drug Therapy, Combination; D005500:Follow-Up Studies; D017273:Goserelin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009570:Nitriles / Q000627:therapeutic use*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D014105:Tosyl Compounds / Q000627:therapeutic use*; D016896:Treatment Outcome
D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D009570:Nitriles; D014105:Tosyl Compounds; D017273:Goserelin; C053541:bicalutamide; D017430:Prostate-Specific Antigen