Predictive value of the cancer of the prostate risk assessment score for recurrence-free survival after radical prostatectomy in Korea: a single-surgeon series

Meta-analysis of predictive models to assess the clinical validity and utility for patient-centered medical decision making: application to the CAncer of the Prostate Risk Assessment (CAPRA)

BACKGROUND

The Cancer of the Prostate Risk Assessment (CAPRA) score was designed and validated several times to predict the biochemical recurrence-free survival after a radical prostatectomy. Our objectives were, first, to study the clinical validity of the CAPRA score, and, second, to assess its clinical utility for stratified medicine from an original patient-centered approach.

METHODS

We proposed a meta-analysis based on a literature search using MEDLINE. Observed and predicted biochemical-recurrence-free survivals were compared to assess the calibration of the CAPRA score. Discriminative capacities were evaluated by estimating the summary time-dependent ROC curve. The clinical utility of the CAPRA score was evaluated according to the following stratified decisions: active monitoring for low-risk patients, prostatectomy for intermediate-risk patients, or radio-hormonal therapy for high risk patients. For this purpose, we assessed CAPRA's clinical utility in terms of its ability to maximize time-dependent utility functions (i.e. Quality-Adjusted Life-Years - QALYs).

RESULTS

We identified 683 manuscripts and finally retained 9 studies. We reported good discriminative capacities with an area under the SROCt curve at 0.73 [95%CI from 0.67 to 0.79], while graphical calibration seemed acceptable. Nevertheless, we also described that the CAPRA score was unable to discriminate between the three medical alternatives, i.e. it did not allow an increase in the number of life years in perfect health (QALYs) of patients with prostate cancer.

CONCLUSIONS

We confirmed the prognostic capacities of the CAPRA score. In contrast, we were not able to demonstrate its clinical usefulness for stratified medicine from a patient-centered perspective. Our results also highlighted the confusion between clinical validity and utility. This distinction should be better considered in order to develop predictive tools useful in practice.

CDC6 mRNA Expression Is Associated with the Aggressiveness of Prostate Cancer

BACKGROUND

Cell division cycle 6 (CDC6) is an essential regulator of DNA replication and plays important roles in the activation and maintenance of the checkpoint mechanisms in the cell cycle. CDC6 has been associated with oncogenic activities in human cancers; however, the clinical significance of CDC6 in prostate cancer (PCa) remains unclear. Therefore, we investigated whether the CDC6 mRNA expression level is a diagnostic and prognostic marker in PCa.

METHODS

The study subjects included 121 PCa patients and 66 age-matched benign prostatic hyperplasia (BPH) patients. CDC6 expression was evaluated using real-time polymerase chain reaction and immunohistochemical (IH) staining, and then compared according to the clinicopathological characteristics of PCa.

RESULTS

CDC6 mRNA expression was significantly higher in PCa tissues than in BPH control tissues (P = 0.005). In addition, CDC6 expression was significantly higher in patients with elevated prostate-specific antigen (PSA) levels (> 20 ng/mL), a high Gleason score, and advanced stage than in those with low PSA levels, a low Gleason score, and earlier stage, respectively. Multivariate logistic regression analysis showed that high expression of CDC6 was significantly associated with advanced stage (≥ T3b) (odds ratio [OR], 3.005; confidence interval [CI], 1.212-7.450; P = 0.018) and metastasis (OR, 4.192; CI, 1.079-16.286; P = 0.038). Intense IH staining for CDC6 was significantly associated with a high Gleason score and advanced tumor stage including lymph node metastasis stage (linear-by-linear association, P = 0.044 and P = 0.003, respectively).

CONCLUSION

CDC6 expression is associated with aggressive clinicopathological characteristics in PCa. CDC6 may be a potential diagnostic and prognostic marker in PCa patients.

The Within-Group Discrimination Ability of the Cancer of the Prostate Risk Assessment Score for Men with Intermediate-Risk Prostate Cancer

BACKGROUND

Significant clinical heterogeneity within contemporary risk group is well known, particularly for those with intermediate-risk prostate cancer (IRPCa). Our study aimed to analyze the ability of the Cancer of the Prostate Risk Assessment (CAPRA) score to discern between favorable and non-favorable risk in patients with IRPCa.

METHODS

We retrospectively reviewed the data of 203 IRPCa patients who underwent extraperitoneal robot-assisted radical prostatectomy (RARP) performed by a single surgeon. Pathologic favorable IRPCa was defined as a Gleason score ≤ 6 and organ-confined stage at surgical pathology. The CAPRA score was compared with two established criteria for the within-group discrimination ability.

RESULTS

Overall, 38 patients (18.7% of the IRPCa cohort) had favorable pathologic features after RARP. The CAPRA score significantly correlated with established criteria I and II and was inversely associated with favorable pathology (all P < 0.001). The area under the receiver operating characteristic curve for the discriminative ability between favorable and non-favorable pathology was 0.679 for the CAPRA score and 0.610 and 0.661 for established criteria I and II, respectively. During a median 37.8 (interquartile range, 24.6-60.2) months of follow-up, 66 patients (32.5%) experienced biochemical recurrence (BCR). Cox regression analysis revealed that the CAPRA score, as a continuous sum score model or 3-group risk model, was an independent predictor of BCR after RARP.

CONCLUSION

The within-group discrimination ability of preoperative CAPRA score might help in patient counseling and selecting optimal treatments for those with IRPCa.

Prostate-specific antigen density predicts favorable pathology and biochemical recurrence in patients with intermediate-risk prostate cancer

This study was designed to identify clinical predictors of favorable pathology and biochemical recurrence (BCR) in patients with intermediate-risk prostate cancer (IRPCa). Between 2006 and 2012, clinicopathological and oncological data from 203 consecutive men undergoing robot-assisted radical prostatectomy (RARP) for IRPCa were reviewed in a single-institutional retrospective study. Favorable pathology was defined as Gleason score ≤6 and organ-confined cancer as detected by surgical pathology. Logistic regression analysis was used to determine predictive variables of favorable pathology, and the Kaplan–Meier and multivariate Cox regression model were used to estimate BCR-free survival after RARP. Overall, 38 patients (18.7%) had favorable pathology after RARP. Lower quartile prostate-specific antigen density (PSAD) was associated with favorable pathology compared to the highest quartile PSAD after adjusting for preoperative PSA, clinical stage and biopsy Gleason score (odds ratio, 5.42; 95% confidence interval, 1.01–28.97; P = 0.048). During a median 37.8 (interquartile range, 24.6–60.2) months of follow-up, 66 patients experienced BCR. There were significant differences with regard to BCR free survival by PSAD quartiles (log rank, P = 0.003). Using a multivariable Cox proportion hazard model, PSAD was found to be an independent predictor of BCR in patients with IRPCa after RARP (hazard ratio, 4.641; 95% confidence interval, 1.109–19.417; P = 0.036). The incorporation of the PSAD into risk assessments might provide additional prognostic information and identify some patients in whom active surveillance would be appropriate in patients with IRPCa.

Lower Levels of Human MOB3B Are Associated with Prostate Cancer Susceptibility and Aggressive Clinicopathological Characteristics

Mps one binder (MOB) proteins are integral components of signaling pathways that control important cellular processes, such as mitotic exit, centrosome duplication, apoptosis, and cell proliferation. However, the biochemical and cellular functions of the human MOB (hMOB) protein family remain largely unknown. The present study investigated the association between hMOB3B expression and clinicopathological characteristics of prostate cancer (PCa).Study subjects included 137 PCa patients and 137 age-matched benign prostatic hyperplasia (BPH) patients. hMOB3B expression was estimated using real-time PCR and compared with clinicopathological parameters of PCa. hMOB3B mRNA expression was significantly lower in PCa tissues than in BPH control tissues (P<0.001). According to receiver operating characteristics curve analysis, the sensitivity of hMOB3B expression for PCa diagnosis was 84.7%, with a specificity of 86% (AUC=0.910; 95% CI=0.869-0.941; P<0.001). hMOB3B expression was significantly lower in patients with elevated prostate specific antigen (PSA) levels (≥10 ng/mL), a Gleason score≥8, and metastatic disease (any T, N+/M+) than in those with low PSA levels, a low Gleason score, and non-metastatic disease (each P<0.05). In conclusion, low levels of hMOB3B are closely associated with aggressive clinicopathologic features in patients with PCa. Our results suggest that hMOB3B may act as a tumor suppressor in human PCa.

Cancer of the Prostate Risk Assessment (CAPRA) Preoperative Score Versus Postoperative Score (CAPRA-S): ability to predict cancer progression and decision-making regarding adjuvant therapy after radical prostatectomy

The University of California, San Francisco, announced in 2011 Cancer of the Prostate Risk Assessment Postsurgical (CAPRA-S) score which included pathologic data, but there were no results for comparing preoperative predictors with the CAPRA-S score. We evaluated the validation of the CAPRA-S score in our institution and compare the result with the preoperative progression predictor, CAPRA score. Data of 130 patients were reviewed who underwent radical prostatectomy for localized prostate cancer from 2008 to 2013. Performance of CAPRA-S score in predicting progression free probabilities was assessed through Kaplan Meier analysis and Cox proportional hazards regression test. Additionally, prediction probability was compared with preoperative CAPRA score by logistic regression analysis. Comparing CAPRA score, the CAPRA-S score showed improved prediction ability for 5 yr progression free survival (concordance index 0.80, P = 0.04). After risk group stratification, 3 group model of CAPRA-S was superior than 3 group model of CAPRA for 3-yr progression free survival and 5-yr progression free survival (concordance index 0.74 vs. 0.70, 0.77 vs. 0.71, P < 0.001). Finally the CAPRA-S score was the more ideal predictor concerned with adjuvant therapy than the CAPRA score through decision curve analysis. The CPARA-S score is a useful predictor for disease progression after radical prostatectomy.