External validation of a nomogram for prediction of side-specific extracapsular extension at robotic radical prostatectomy.
OBJECTIVE
Several staging tools have been developed for open radical prostatectomy (ORP) patients. However, the validity of these tools has never been formally tested in patients treated with robot-assisted laparoscopic radical prostatectomy (RALP). We tested the accuracy of an ORP-derived nomogram in predicting the rate of extracapsular extension (ECE) in a large RALP cohort.


METHODS
Serum prostate specific antigen (PSA) and side-specific clinical stage and biopsy Gleason sum information were used in a previously validated nomogram predicting side-specific ECE. The nomogram-derived predictions were compared with the observed rate of ECE, and the accuracy of the predictions was quantified. Each prostate lobe was analyzed independently. As complete data were available for 576 patients, the analyses targeted 1152 prostate lobes. Median age and serum PSA concentration at radical prostatectomy were 60 years and 5.4 ng/mL, respectively.


RESULTS
The majority of side-specific clinical stages were T(1c) (993; 86.2%). Most side-specific biopsy Gleason sums were 6 (572; 49.7%). The median side-specific percentages of positive cores and of cancer were, respectively, 20.0% and 5.0%. At final pathologic review, 107 patients (18.6%) had ECE, and side-specific ECE was present in 117 patients (20.3%). The nomogram was 89% accurate in the RALP cohort v 84% in the previously reported ORP validation.


CONCLUSIONS
The ORP side-specific ECE nomogram is highly accurate in the RALP population, suggesting that predictive and possibly prognostic tools developed in ORP patients may be equally accurate in their RALP counterparts.
Minimal Invasive Urology Department, University of Chicago, Chicago, Illinois, USA.
Kevin C
KC
Zorn
Andrea
A
Gallina
Georg C
GC
Hutterer
Jochen
J
Walz
Arieh L
AL
Shalhav
Gregory P
GP
Zagaja
Luc
L
Valiquette
Ofer N
ON
Gofrit
Marcelo A
MA
Orvieto
Jerome B
JB
Taxy
Pierre I
PI
Karakiewicz
D006801:Humans; D016015:Logistic Models; D008297:Male; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D049451:Nomograms; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000295:instrumentation*; D011471:Prostatic Neoplasms / Q000473:pathology*; D012371:Robotics / Q000295:instrumentation*
D017430:Prostate-Specific Antigen