Development and internal validation of a nomogram predicting the probability of prostate cancer Gleason sum upgrading between biopsy and radical prostatectomy pathology.
OBJECTIVE
Previous reports indicate that as many as 43% of men with low grade PCa at biopsy will be diagnosed with high-grade PCa at RP. We explored the rate of upgrading from biopsy to RP specimen in our contemporary cohort, and developed a model capable of predicting the probability of biopsy Gleason sum upgrading.


METHODS
The study cohort consisted of 2982 men treated with RP, with available clinical stage, serum prostate specific antigen and biopsy Gleason scores. These clinical data were used as predictors in multivariate logistic regression models (LRM) addressing the rate of Gleason sum upgrading between biopsy and RP pathology. LRM regression coefficients were used to develop a nomogram predicting the probability of Gleason sum upgrading and was subjected to 200 bootstrap resamples for internal validation and to reduce overfit bias.


RESULTS
Overall, 875 patients were upgraded (29.3%). In multivariate LRMs, all predictors were highly significant (all p values <0.0001). Bootstrap-corrected predictive accuracy of the nomogram predicting the probability of Gleason sum upgrading between biopsy and RP was 0.804.


CONCLUSIONS
We developed a highly accurate clinical aid for treatment decision-making. It may prove useful when the possibility of a more aggressive Gleason variant may change the treatment options.
Chun
Felix K-H
FK
Department of Urology, University of Hamburg, Hamburg, Germany.
Steuber
Thomas
T
Erbersdobler
Andreas
A
Currlin
Eike
E
Walz
Jochen
J
Schlomm
Thorsten
T
Haese
Alexander
A
Heinzer
Hans
H
McCormack
Michael
M
Huland
Hartwig
H
Graefen
Markus
M
Karakiewicz
Pierre I
PI
D001706:Biopsy; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D049451:Nomograms; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012720:Severity of Illness Index
D017430:Prostate-Specific Antigen