Tumour volume and high grade tumour volume are the best predictors of pathologic stage and biochemical recurrence after radical prostatectomy.
BACKGROUND
Our goal was to examine to what extent tumour volume (TV) and percentage of high grade tumour volume (%HGTV) affect the rate of positive surgical margins and the rate of biochemical recurrence after radical prostatectomy.


METHODS
TV and %HGTV were routinely planimetrically quantified in a cohort of 780 consecutive patients. Mean follow-up was 46.7 months. Multivariable regression models addressed two separate endpoints: positive surgical margins and biochemical recurrence. The increase in model predictive accuracy related to the addition of TV and %HGTV to radical prostatectomy stage and grade was assessed, after 200 bootstrap resamples to reduce overfit bias.


RESULTS
In multivariable logistic regression models addressing positive surgical margins rate, predictive accuracy increased by 1.9% (p<0.001) when TV was added to other covariates. No further increment was noted when %HGTV was added (p=0.3). In multivariable Cox regression models addressing biochemical recurrence, accuracy increased by 0.6% (p=0.002) when TV was added and an additional increase of 0.7% was recorded when %HGTV (p<0.001) was added.


CONCLUSIONS
Tumour bulk reflected by TV affects local cancer control rate, which is reflected in the rate of positive surgical margins. Conversely, high grade cancer determines the rate of biochemical recurrence. These two variables represent the most powerful predictors of cancer control in men treated for localised prostate cancer. Moreover, they increase the ability of established predictors to predict the outcomes of interest. In consequence, they warrant consideration in future predictive and prognostic tools.
Chun
Felix K-H
FK
Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center (CHUM), 1058, Rue St-Denis, Montreal, Que., Canada H2X 3J4.
Briganti
Alberto
A
Jeldres
Claudio
C
Gallina
Andrea
A
Erbersdobler
Andreas
A
Schlomm
Thorsten
T
Walz
Jochen
J
Eichelberg
Christian
C
Salomon
Georg
G
Haese
Alexander
A
Currlin
Eike
E
Ahyai
Sascha A
SA
Bénard
François
F
Huland
Hartwig
H
Graefen
Markus
M
Karakiewicz
Pierre I
PI
D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods*; D009929:Organ Size; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery
D017430:Prostate-Specific Antigen