Early PSA decrease is an independent predictive factor of clinical failure and specific survival in patients with localized prostate cancer treated by radiotherapy with or without androgen deprivation therapy.
BACKGROUND
The aim was to identify predictors of outcome in patients with localized prostate cancer treated with external beam radiotherapy (EBRT), with or without androgen deprivation therapy (ADT).


METHODS
A total of 448 patients with prostate cancer received EBRT alone (n = 361, group 1) or ADT followed by EBRT (n = 87, group 2). In group 2, ADT was initiated 3 months before EBRT. After baseline prostate-specific antigen (PSA) determination (PSA(preRT)), PSA was assessed during the 6th week of the EBRT course (PSA(6wRT)) in group 1. In group 2, PSA was measured again 3 months after the start of ADT, before EBRT (PSA(ADT-preRT)).


RESULTS
In group 1, median PSA(6wRT)/PSA(preRT) was 0.72 and median prostate-specific antigen velocity (PSAV) was -1.5 ng/ml/month. In the multivariate analysis, prognostic groups and PSA(6wRT)/PSA(preRT) (or PSAV) independently predicted biochemical failure (BF), clinical failure (CF), and prostate cancer-specific survival. In group 2, the median PSA(ADT-preRT) was 1.3 ng/ml. In the high-risk group, an undetectable PSA(ADT-preRT) (< or =0.2 ng/ml) predicted BF (P < 0.01) and CF (P = 0.007).


CONCLUSIONS
A PSA decline 6 weeks after the start of EBRT when used as monotherapy and 3 months after the start of ADT in patients treated with combined ADT and EBRT is predictive of progression and specific survival.
de Crevoisier
R
R
Department of Radiation, Institut Gustave-Roussy, Villejuif; Departement de Radiotherapie, Centre Eugène Marquis, Avenue Bataille Flandre Dunkerque, Rennes; Departments of. Electronic address: brdecrevoisier2000@yahoo.fr.
Slimane
K
K
Department of Medicine.
Messai
T
T
Department of Radiation, Institut Gustave-Roussy, Villejuif.
Wibault
P
P
Department of Radiation, Institut Gustave-Roussy, Villejuif.
Eschwege
F
F
Department of Radiation, Institut Gustave-Roussy, Villejuif.
Bossi
A
A
Department of Radiation, Institut Gustave-Roussy, Villejuif.
Koscielny
S
S
Department of Biostatistics and Epidemiology, Institut Gustave-Roussy, Villejuif, France.
Bridier
A
A
Department of Radiation, Institut Gustave-Roussy, Villejuif.
Massard
C
C
Department of Medicine.
Fizazi
K
K
Department of Medicine.
D000230:Adenocarcinoma / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001918:Brachytherapy; D003131:Combined Modality Therapy; D015536:Down-Regulation; D042241:Early Diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000532:radiotherapy*; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D017211:Treatment Failure
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D017430:Prostate-Specific Antigen