Prostate-specific antigen nadir and cancer-specific mortality following hormonal therapy for prostate-specific antigen failure.
OBJECTIVE
For men receiving androgen-suppression therapy (AST) for a rising postoperative or postradiation prostate-specific antigen (PSA), we evaluated whether a PSA nadir of more than 0.2 ng/mL was significantly associated with prostate cancer-specific mortality (PCSM).


METHODS
The study cohort comprised 747 men with rising PSA and negative bone scan after surgery (n = 486) or radiation therapy (n = 261) who were treated with AST. Cox regression was used to evaluate whether a significant association existed between the PSA nadir level after 8 months of AST and the time to PCSM, controlling for treatment and known prognostic factors.


RESULTS
The post-AST PSA nadir (pCox < .0001), the pre-AST PSA doubling time (DT) (pCox = .002), PSA level (P = .0001), and Gleason eight to 10 cancers (pCox = .01) were significantly associated with time to PCSM. The adjusted hazard ratio for PCSM was 20 (95% CI, 7 to 61; pCox < .0001), for men with a PSA nadir of more than 0.2 ng/mL as compared with all others. A PSA DT of less than 3 months was observed in 30% (224 of 747) of the study cohort. Of the 28 observed prostate cancer deaths, 21 (75%) occurred in men whose PSA nadir was more than 0.2 ng/mL and who had a PSA DT of less than 3 months.


CONCLUSIONS
A PSA nadir of more than 0.2 ng/mL after 8 months of AST given for postoperative or postradiation PSA failure is significantly associated with PCSM and is clinically significant because it accounted for 75% of the cancer deaths observed in this study.
Stewart
Alexandra J
AJ
Brigham and Women's Hospital, Dana-Faber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA. ajsintheus@yahoo.co.uk
Scher
Howard I
HI
Chen
Ming-Hui
MH
McLeod
David G
DG
Carroll
Peter R
PR
Moul
Judd W
JW
D'Amico
Anthony V
AV
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D015331:Cohort Studies; D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000401:mortality* / Q000601:surgery; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D016896:Treatment Outcome
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen