Evaluation of four pre-operative models for prediction of biochemical
recurrence after radical prostatectomy in localized prostate cancer
Abstract
Background: Biochemical recurrence (BCR) can be seen in the early or
late period after radical prostatectomy (RP). Various models have been
developed to predict BCR. Objective: In our study we evaluated accuracy
of four pre-operative models (GP score, PRIX, D’Amico risk
classification, CAPRA) in predicting BCR after RP in Turkish patients.
Methods: Age, preoperative total prostate specific antigen (PSA) values,
clinical stages, total number of cores taken in biopsy, number of
positive cores, preoperative biopsy Gleason score (GS), follow-up time
and presence of BCR after RP were recorded. BCR was defined as a total
PSA value > 0.2 ng / dl twice consecutively after RP.
Classifications or scoring was performed according to pre-operative
models. The 1, 3 and 5 year (yr) BCR-free rates of the patients were
determined for each model. Also the accuracy of four predictive models
for predicting 1, 3 and 5-yr BCR was evaluated. Results: For all
pre-operative models there was statistically significant difference
between risk groups in BCR free rates at 1, 3 and 5-yr after RP
(p<0.001). The Harrell’s concordance index for 1-yr BCR
predictions was 0,802, 0,831, 0,773 and 0,745 for the GP score, PRIX,
CAPRA and D’Amico and respectively. For 3-yr BCR predictions it was
0,798, 0,791, 0,723 and 0,714 for the GP score, PRIX, CAPRA and D’Amico
and respectively. Finally, The Harrell’s concordance index for 5-yr BCR
predictions was 0,778, 0,771, 0,702 and 0,693 for the GP score, PRIX,
CAPRA and D’Amico and respectively. Conclusion: In prediction of BCR,
accuracy of GP scoring and PRIX seems slightly higher than CAPRA and
D’Amico risk classification. Surely our results should be supported by
head to head comparisons with in other larger cohorts