Prognostic significance of baseline reverse transcriptase-PCR for prostate-specific antigen in men with hormone-refractory prostate cancer treated with chemotherapy.
OBJECTIVE
Methods accurately categorizing the diverse biology of prostate cancer are needed. A positive baseline reverse transcriptase-PCR for prostate-specific antigen (RT-PCR PSA) in the androgen-independent setting is an independent prognostic marker of survival. The objectives of the current study were to examine the prognostic implication of baseline RT-PCR PSA positivity during treatment with an active chemotherapeutic agent and explore whether an RT-PCR PSA "response" provides prognostic information.


METHODS
In a combined analysis of a phase I and a randomized phase II trial of BMS-247550 (an epothilone B analogue), 104 patients with hormone-refractory prostate cancer had whole blood samples collected at baseline, then with each cycle of therapy. RT-PCR PSA was assessed and related to time to progression (TTP).


RESULTS
From 100 evaluable patients, 368 samples were received, of which 90.8% were evaluable for RT-PCR PSA status. Baseline RT-PCR PSA status was significantly associated with TTP (hazard ratio, 2.22; 95% confidence interval, 1.40-3.52). Twenty-six of 38 patients positive at first assessment had at least one follow-up RT-PCR PSA that was negative ("response"). In univariate analysis, RT-PCR PSA response was not significantly associated with TTP, but in multivariate analysis, RT-PCR PSA response was of borderline statistical significance in predicting TTP (hazard ratio, 0.41; 95% confidence interval, 0.16-1.01).


CONCLUSIONS
These results provide further confirmation that baseline RT-PCR PSA is a statistically significant predictor of TTP in hormone-refractory prostate cancer. Moreover, this is the first report to suggest that RT-PCR PSA response during chemotherapy treatment may predict TTP.
Ross
Robert W
RW
Dana-Farber Cancer Institute, Harvard Medical School Boston, Massachusetts 02115, USA. rwross@partners.org
Manola
Judith
J
Hennessy
Kristen
K
Galsky
Matthew
M
Scher
Howard
H
Small
Eric
E
Kelly
W Kevin
WK
Kantoff
Philip W
PW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000096:biosynthesis*; D018450:Disease Progression; D019008:Drug Resistance, Neoplasm; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000096:biosynthesis*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen