Quantitative RT-PCR analysis of PSA and prostate-specific membrane antigen mRNA to detect circulating tumor cells improves recurrence-free survival nomogram prediction after radical prostatectomy.
BACKGROUND
Circulating tumor cell (CTC) analysis is a potential new biomarker in prostate cancer. We hypothesize that quantitative detection of CTCs in patients pre- and post-radical prostatectomy (RP) using quantitative TaqMan® fluorogenic RT-PCR will improve the accuracy of the Kattan nomogram to predict the probability of recurrence-free survival (RFS) post-RP.


METHODS
Ninty-two patients who underwent RP between 2004 and 2009 had venous blood samples taken pre- (Day - 1) and post-operatively (Day + 7). We performed quantitative Taqman® RT-PCR to detect circulating prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) mRNA. We calculated both the logarithmic ratio of Day + 7/Day - 1 for PSA (PSAr) and PSMA (PSMAr) expression (log(Day+7/Day-1) ) and the Kattan nomogram predicted probability of disease recurrence for each patient. We then analyzed how the AUC-ROC analysis for the Kattan nomogram prediction alone (K) compared to the addition of the PSAr and PSMAr in predicting 5-year RFS.


RESULTS
The mean age (years), PSA (ng/ml), and follow-up (mo) was 65.1, 9.13, and 72, respectively. The AUCs for K, PSAr + K, and PSMAr + K were 0.752 (95%CI 0.620-0.860), 0.830 (95%CI 0.740-0.911), and 0.837 (95%CI 0.613-0.923), respectively (P = 0.03). The Kattan 5-year PSA RFS was 75%. The actual 5-year PSA RFS survival rate was 77%.


CONCLUSIONS
Data from modern quantitative RT-PCR to detect circulating prostate-derived PSA and PSM mRNA pre- and post-RP improves the accuracy of the Kattan nomogram to predict biochemical recurrence.
Faculté de Médecine Pierre et Marie Curie, Academic Department of Urology of la Pitie Salpetriere Hospital, Assistance Publique-Hôpitaux de Paris, University Paris VI, 75013 Paris, France.
David R
DR
Yates
Morgan
M
Rouprêt
Sarah J
SJ
Drouin
Eva
E
Comperat
Sylvie
S
Ricci
Roger
R
Lacave
Philippe
P
Sèbe
Geraldine
G
Cancel-Tassin
Marc-Olivier
MO
Bitker
Olivier
O
Cussenot
D000368:Aged; D000954:Antigens, Surface / Q000097:blood / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D043425:Glutamate Carboxypeptidase II / Q000097:blood / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000235:genetics / Q000401:mortality; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D049451:Nomograms; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000737:chemistry / Q000235:genetics*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012008:Recurrence
D000954:Antigens, Surface; D014408:Biomarkers, Tumor; D012333:RNA, Messenger; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II; D017430:Prostate-Specific Antigen