Prediction of disease progression indicators in prostate cancer patients receiving HDR-brachytherapy using Raman spectroscopy and semi-supervised learning: a pilot study

This work combines Raman spectroscopy (RS) with supervised learning methods-group and basis restricted non-negative matrix factorisation (GBR-NMF) and linear discriminant analysis (LDA)-to aid in the prediction of clinical indicators of disease progression in a cohort of 9 patients receiving high dose rate brachytherapy (HDR-BT) as the primary treatment for intermediate risk (D'Amico) prostate adenocarcinoma. The combination of Raman spectroscopy and GBR-NMF-sparseLDA modelling allowed for the prediction of the following clinical information; Gleason score, cancer of the prostate risk assessment (CAPRA) score of pre-treatment biopsies and a Ki67 score of < 3.5% or > 3.5% in post treatment biopsies. The three clinical indicators of disease progression investigated in this study were predicted using a single set of Raman spectral data acquired from each individual biopsy, obtained pre HDR-BT treatment. This work highlights the potential of RS, combined with supervised learning, as a tool for the prediction of multiple types of clinically relevant information to be acquired simultaneously using pre-treatment biopsies, therefore opening up the potential for avoiding the need for multiple immunohistochemistry (IHC) staining procedures (H&E, Ki67) and blood sample analysis (PSA) to aid in CAPRA scoring.

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.

Whom to Treat: Postdiagnostic Risk Assessment with Gleason Score, Risk Models, and Genomic Classifier

Management of prostate cancer presents unique challenges because of the disease's variable natural history. Accurate risk stratification at the time of diagnosis in clinically localized disease is crucial in providing optimal counseling about management options. To accurately distinguish pathologically indolent tumors from aggressive disease, risk groups are no longer sufficient. Rather, multivariable prognostic models reflecting the complete information known at time of diagnosis offer improved accuracy and interpretability. After diagnosis, further testing with genomic assays or other biomarkers improves risk classification. These postdiagnostic risk assessment tools should not supplant shared decision making, but rather facilitate risk classification and enable more individualized care.

Significance of preoperative butyrylcholinesterase as an independent predictor of biochemical recurrence-free survival in patients with prostate cancer treated with radical prostatectomy

BACKGROUND

Butyrylcholinesterase (BChE) is an alpha-glycoprotein found in the nervous system and liver. Its serum level is reduced in many clinical conditions, such as liver damage, inflammation, injury, infection, malnutrition, and malignant disease. In this study, we analyzed the potential prognostic significance of preoperative BChE levels in patients with prostate cancer (PCa) undergoing radical prostatectomy (RP).

METHODS

We retrospectively evaluated 535 patients with PCa who underwent RP from 1996-2014 at a single institution. Serum BChE was routinely measured in all patients before operation. Covariates included age, preoperative laboratory data [prostate-specific antigen (PSA), hemoglobin, total protein, albumin, BChE, lactate dehydrogenase, C-reactive protein], clinical T, biopsy Gleason score, D'Amico risk classification, and RP with/without neoadjuvant therapy. Univariate and multivariate analyses were performed to identify clinical factors associated with biochemical recurrence-free survival (BRFS). Univariate analyses were performed using the Kaplan-Meier and log-rank methods, and multivariate analysis was performed using a Cox proportional hazard model.

RESULTS

The median BChE level was 255 U/L (normal range 168-470 U/L). The median age of the enrolled patients was 68 years, and the median PSA level at diagnosis of PCa was 8.39 ng/mL. The median follow-up period was 65 months. The 5-year BRFS rate was 72.9 %. The 5-year BRFS rates in the BChE ≥ 168 and ≤ 167 U/L groups were 77.7 and 55.0 %, respectively (P < 0.001). In univariate analysis, BChE, cT, biopsy Gleason score, and D'Amico risk classification were significantly associated with BRFS. Multivariate analysis revealed that BChE was significantly associated with BRFS.

CONCLUSIONS

This study validated preoperative serum BChE levels as an independent prognostic factor for PCa after RP.

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.

Efficiency of pretreatment risk stratification systems for prostate cancer in a Japanese population treated with radical prostatectomy

OBJECTIVE

To determine whether the currently available pretreatment risk classification systems are applicable in Japanese prostate cancer patients.

METHODS

Using data obtained from 1264 consecutive patients with prostate cancer treated with radical prostatectomy at four hospitals in Japan, biochemical recurrence-free survival rates were estimated and compared between the D'Amico, the National Institute for Health and Clinical Excellence, the Cancer of the Prostate Strategic Urological Research Endeavor, the National Comprehensive Cancer Network, and the European Society of Medical Oncology risk groups by using the Kaplan-Meier method and log-rank test.

RESULTS

The 5-year biochemical recurrence-free survival rates in the D'Amico low-, intermediate-, and high-risk groups were 88.3%, 84.7% and 66.9%, respectively (low and intermediate risk vs high risk, P < 0.001). The 5-year biochemical recurrence-free survival rates in the National Institute for Health and Clinical Excellence, National Comprehensive Cancer Network, and European Society of Medical Oncology low-, intermediate- and high-risk groups were 88.3%, 84.3%, and 60.3%, respectively (low and intermediate risk vs high risk, P < 0.001). The 5-year biochemical recurrence-free survival rates in the Cancer of the Prostate Strategic Urological Research Endeavor low-, intermediate-, and high-risk groups were 90%, 83.5% and 60.3%, respectively (low and intermediate risk vs high risk, P < 0.001). Low- and intermediate-risk groups according to any of the risk stratification systems did not show significant differences in biochemical recurrence-free survival.

CONCLUSION

Current risk stratification systems do not discriminate between low- and intermediate-risk groups in the Japanese population. A novel, pretreatment risk stratification system including other prognostic factors is necessary for an adequate prostate cancer risk assessment in the Japanese population.

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

Purpose

To evaluate the validity of the cancer of the prostate risk assessment (CAPRA) score, a newly developed nomogram for preoperative prediction of recurrence after radical prostatectomy, in a single institution in Korea.

Materials and Methods

We retrospectively studied 115 men who had undergone radical prostatectomy as the first treatment for localized prostate cancer. The validity of the CAPRA score for the prediction of recurrence-free survival (RFS) and pathologic outcome was evaluated by using Kaplan-Meier analysis and a proportional hazards regression model. A seven-group model and a three-group model were used for the results.

Results

None of the variables of the CAPRA score was favorable compared with the previously reported data. The three-group model was significantly related with 3- and 5-year RFS (p<0.05), but the seven-group model was not. The concordance indices of the CAPRA score were 0.74 and 0.77. Of four components excluding the clinical T stage, three independently predicted RFS (age, Gleason sum, and percentage of positive biopsies). The CAPRA score was significantly related to the margin status, extracapsular extension, and seminal vesicle invasion in both the seven- and three-group models. In the three-group model, pathologic outcomes were more strongly related, especially a higher risk of seminal vesicle invasion.

Conclusions

The CAPRA score showed high accuracy for predicting RFS. In particular, the three-group model was more useful for predicting RFS and pathologic outcomes. Therefore, the CAPRA score may be a useful prediction model for risk stratification and may help clinicians to develop localized prostate cancer treatment.

Prognostic value of the CAPRA clinical prediction rule: a systematic review and meta-analysis

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Prostate cancer is a significant cause of mortality among men. A number of prognostic instruments exist to predict the risk of recurrence among patients with localised prostate cancer. This systematic review examines the totality of evidence in relation to the predictive value of the CAPRA clinical predication rule by combining all studies that validate the rule.

OBJECTIVES

To perform a systematic review with meta-analysis that assesses the 3- and 5-year predictive value of the CAPRA rule, a clinical prediction rule derived to predict biochemical-recurrence-free survival in men with localized prostate cancer after radical prostatectomy. To examine the predictive value of the CAPRA rule at 3 and 5 years stratified by risk group (0-2 low risk, 3-5 intermediate risk, 6-10 high risk).

PATIENTS AND METHODS

A systematic literature search was performed to retrieve papers that validated the CAPRA score. The original derivation study was used as a predictive model and applied to all validation studies with observed and predicted biochemical-recurrence-free survival at 3 and 5 years stratified by risk group (0-2 low, 3-5 intermediate, 6-10 high). Pooled results are presented as risk ratios (RRs) with 95% confidence intervals, in terms of over-prediction (RR > 1) or under-prediction (RR < 1) of biochemical-recurrence-free survival at 3 and 5 years. A chi-squared test for trend was computed to determine if there was a decreasing trend in survival across the three CAPRA risk categories.

RESULTS

Seven validation studies (n = 12 693) predict recurrence-free survival at 5 years after radical prostatectomy. The CAPRA score significantly under-predicts recurrence-free survival across all three risk strata (low risk, RR 0.94, 95% CI 0.90-0.98; intermediate risk, RR 0.94, 95% CI 0.89-0.99; high risk, RR 0.72, 95% CI 0.60-0.85). Data on six studies (n = 6082) are pooled to predict 3-year recurrence-free survival. The CAPRA score correctly predicts recurrence-free survival in all three groups (low risk, RR 0.98, 95% CI 0.95-1.00; intermediate risk, RR 1.03, 95% CI 0.99-1.08; high risk, RR 0.87, 95% CI 0.73-1.05). The chi-squared trend analysis indicates that, as the trichotomized CAPRA score increases, the probability of survival decreases (P < 0.001).

CONCLUSIONS

The results of this pooled analysis confirm the ability of the CAPRA rule to correctly predict biochemical-recurrence-free survival at 3 years after radical prostatectomy. The rule under-predicts recurrence-free survival 5 years after radical prostatectomy across all three strata of risk.