Interobserver variability between expert urologic pathologists for extraprostatic extension and surgical margin status in radical prostatectomy specimens.
Accurate Gleason score, pathologic stage, and surgical margin (SM) information is critical for the planning of post-radical prostatectomy management in patients with prostate cancer. Although interobserver variability for Gleason score among urologic pathologists has been well documented, such data for pathologic stage and SM assessment are limited. We report the first study to address interobserver variability in a group of expert pathologists concerning extraprostatic soft tissue (EPE) and SM interpretation for radical prostatectomy specimens. A panel of 3 urologic pathologists selected 6 groups of 10 slides designated as being positive, negative, or equivocal for either EPE or SM based on unanimous agreement. Twelve expert urologic pathologists, who were blinded to the panel diagnoses, reviewed 40x whole-slide scans and provided diagnoses for EPE and SM on each slide. On the basis of panel diagnoses, as the gold standard, specificity, sensitivity, and accuracy values were high for both EPE (87.5%, 95.0%, and 91.2%) and SM (97.5%, 83.3%, and 90.4%). Overall kappa values for all 60 slides were 0.74 for SM and 0.63 for EPE. The kappa values were higher for slides with definitive gold standard EPE (kappa=0.81) and SM (kappa=0.73) diagnoses when compared with the EPE (kappa=0.29) and SM (kappa=0.62) equivocal slides. This difference was markedly pronounced for EPE. Urologic pathologists show good to excellent agreement when evaluating EPE and SM. Interobserver variability for EPE and SM interpretation was principally related to the lack of a clearly definable prostatic capsule and crush/thermal artifact along the edge of the gland, respectively.
Evans
Andrew J
AJ
Department of Pathology and Laboratory Medicine, University Health Network, Toronto, Ontario, Canada. andrew.evans@uhn.on.ca
Henry
Pauline C
PC
Van der Kwast
Theodorus H
TH
Tkachuk
Douglas C
DC
Watson
Kemp
K
Lockwood
Gina A
GA
Fleshner
Neil E
NE
Cheung
Carol
C
Belanger
Eric C
EC
Amin
Mahul B
MB
Boccon-Gibod
Liliane
L
Bostwick
David G
DG
Egevad
Lars
L
Epstein
Jonathan I
JI
Grignon
David J
DJ
Jones
Edward C
EC
Montironi
Rodolfo
R
Moussa
Madeleine
M
Sweet
Joan M
JM
Trpkov
Kiril
K
Wheeler
Thomas M
TM
Srigley
John R
JR
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D005060:Europe; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D009656:North America; D015588:Observer Variation; D010340:Pathology, Surgical; D018579:Patient Selection; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology* / Q000601:surgery; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014572:Urology