Comparison of cell cycle progression (CCP) score to two IHC markers (PTEN and Ki-67) for predicting outcome in prostate cancer after radical prostatectomy.
INTRODUCTION
Previous studies of the cell cycle progression (CCP) score in surgical specimens of prostate cancer in patients treated by radical prostatectomy (RP) demonstrated a significant association with time to biochemical recurrence (BCR). In this study, we evaluated and compared the ability of the CCP score and the expression of PTEN or Ki-67 to predict BCR ina cohort of patients treated by RP. Finally, we constructed the best predictive model for BCR incorporating the biomarkers and relevant clinical variables.
METHODS
The study population consisted of 652 prostate cancer patients enrolled in a retrospective cohort and who had RP surgery in French urological centers from 2000 to 2007.
RESULTS
Among the 652 patients with CCP scores and complete clinical data, BCR events occurred in 41%, and time from surgery to last follow up among patients free of BCR was 72 months (Table 1). In univariate Cox analysis, the continuous CCP score and positive Ki-67 predicted recurrence with an HR of 1.44 (95% CI: 1.17-1.75; p=5.3 x 10-4) and 1.89 (95% CI: 1.38-2.57; p=1.6 x 10-4), respectively (Table 2). In contrast, PTEN expression wasn't associated with the risk of BCR. Of the 3 biomarkers, only the CCP score remained significantly associated in multivariable Cox model (p = 0.026) (Table 3). The best model incorporated CAPRA-S and CCP scores as predictors, with HR of 1.32 and 1.24, respectively.
CONCLUSION
CCP score was superior to the two IHC markers (PTEN and Ki-67) for predicting outcome in prostate cancer after radical prostatectomy.
Funding: Study conducted with the financial support of Myriad Genetics SAS