Serum PSA half-life as a predictor of survival for hormone-refractory prostate cancer patients: modelization using a standardized set of response criteria.
OBJECTIVE
Changes of serum prostate-specific antigen (PSA) during chemotherapy have been validated as a marker of response for hormone-refractory prostate cancer (HRPC) patients. We retrospectively established new response criteria to assess the risk of death.


METHODS
Two hundred fifty-six chemonaive HRPC patients treated with chemotherapy were included in the analysis. According to PSA half-life (HL) dynamics, three response categories were defined: responders (R), late-progressors (LP) and initial-progressors (IP), that were compared with Working Group (WG) criteria. PSA HL time to failure (TTF) and overall survival (OS) were estimated and compared between HT categories. Multivariate regression analysis was performed to isolate the impact on OS of these response categories. A new predictor of survival, delta-time PSA interval (DeltaT) was described.


RESULTS
PSA HL categories were strongly related with WG criteria (P = 0.0001). PSA HL TTF differed among PSA HL categories: 4.2, 2.3, and 0.9 months for R, LP, and IP patients, respectively, and their respective median OS were 27, 19.7, and 12.3 months (P = 0.0001). For DeltaT > or = 3 versus <3 months, median OS significantly differed: 24.9 months versus 13.2 months (P = 0.0001).


CONCLUSIONS
PSA HL dynamics during chemotherapy were able to accurately predict survival, earlier than WG-defined progression criteria. This criterion should be prospectively evaluated in randomized trials for HRPC patients in order to better estimate the risk of death.
Banu
Eugeniu
E
Medical Oncology Department, Georges Pompidou European Hospital, Paris, France. banu-eugeniu@yahoo.fr
Banu
Adela
A
Medioni
Jacques
J
Levy
Eric
E
Thiounn
Nicolas
N
Mejean
Arnaud
A
Andrieu
Jean-Marie
JM
Oudard
Stephane
S
D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000556:secondary; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000401:mortality / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen