Surgical volume is related to the rate of positive surgical margins at radical prostatectomy in European patients.
OBJECTIVE
To assess the association between surgical volume (SV) and the rate of positive surgical margins (PSM) after radical prostatectomy (RP) in a large single-institution European cohort of patients.


METHODS
In all, 2402 men had a RP by a group of 11 surgeons, all of whom were trained by the surgeon with the highest SV; all surgeons used the same surgical technique. Variables assessed before RP were prostate-specific antigen (PSA) level, clinical stage and biopsy Gleason sum; variables assessed after RP were PSA level, extracapsular extension, seminal vesicle invasion, lymph node invasion and pathological Gleason sum. These were used to predict the rate of PSM in models before or after RP. Multivariate models were complemented with SV to test its independent and multivariate statistical significance and to quantify its impact on the model's overall (and 200 bootstrap-corrected) predictive accuracy.


RESULTS
The mean (range) SV was 201 (1-1293) RPs; the mean (median, range) rate of PSM was 20.2 (21.4, 0-32.9)%. In multivariate models, SV was a highly statistically significant independent predictor of PSM (P < 0.001) and increased the predictive accuracy in multivariate models both before (2.0%) and after RP (1.5%, both P < 0.001). However, when the surgeon with the highest SV, who contributed to 1293 cases, was removed from the analyses, the multivariate independent prediction and the gains in predictive accuracy related to adding SV, disappeared in the models both before (P = 0.9, accuracy gain 0.1%) and after (P = 0.4, accuracy gain - 0.3%) RP.


CONCLUSIONS
These results indicate that patients treated by surgeons with a very high volume can expect to have a significantly lower rate of PSM, after accounting for clinical and pathological case-mix differences. However, SV is not a predictor of PSM when analyses are restricted to intermediate- and low-volume surgeons.
Chun
Felix K-H
FK
Cancer Prognostics and Health Outcomes Unit, University of Montreal, Montreal, Quebec, Canada.
Briganti
Alberto
A
Antebi
Elie
E
Graefen
Markus
M
Currlin
Eike
E
Steuber
Thomas
T
Schlomm
Thorsten
T
Walz
Jochen
J
Haese
Alexander
A
Friedrich
Martin G
MG
Ahyai
Sascha A
SA
Eichelberg
Christian
C
Salomon
Georg
G
Gallina
Andrea
A
Erbersdobler
Andreas
A
Perrotte
Paul
P
Heinzer
Hans
H
Huland
Hartwig
H
Karakiewicz
Pierre I
PI
D002983:Clinical Competence / Q000592:standards*; D015331:Cohort Studies; D005060:Europe; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D015999:Multivariate Analysis; D018365:Neoplasm, Residual; D011379:Prognosis; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000592:standards / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
D017430:Prostate-Specific Antigen