[CAPRA score vs minimal residual disease as predictors of biochemical recurrence after radical prostatectomy.]

OBJECTIVE

To compare the classification CAPRA (based on clinical-pathological findings) and minimal residual disease (MRD) (based on biological characteristics) to predict biochemical failure (BF).

METHOD AND PATIENTS

The clinical-pathological findings of the prostate biopsy were used to determine the CAPRA score, classifying patients into low, intermediate and high risk. Blood and bone marrow samples to detect circulating prostate cells (CPCs) and micro-metastasis were taken. The samples were classified as positive if ≥1 prostate cell was detected, forming three subgroups; Group A (MRD negative), Group B (micro-metastasis positive, CPC negative) and Group C (CPC positive). Patients were followed-up for 10 yearsor BF. Kaplan-Meier biochemical failure free survival (BFFS) curves, a predictive flexible parameter survival model and mean restricted survival times (MRST) were determined.

RESULTS

347 men participated, BF risk increased with increasing CAPRA score, HR 1.21 intermediate, 1.64 high risk; versus MRD HR 1.91 and 4.43 for Groups Band C. After 10 years the BFFS and MRST were 76%, 50% and 17% and 9, 7 and 5 years respectively for CAPRA versus 94%, 57% and 26% and 10, 9 and 6 years respectively for MRD. The concordance between observed and predicted BFFS was acceptable for CAPRA (Harrell´s C 0.64) and very good (0.92) for MRD. The BFFS curves for MRD were not proportional with time, they were similar for 5 years for Groups A and B, with increasing BFFS in Group B there after.The CAPRA score did not distinguish between Groups A and B, one third of low risk CAPRA patients had CPCs detected.

CONCLUSIONS

The MRD classification was superior to CAPRA, differentiating between early and late failure.

Validity of the Cancer of the Prostate Risk Assessment Score Derived From Targeted Biopsy: Modeling Evidence From Ultrasound Lesion-Directed Biopsy

OBJECTIVE

Our aim was to evaluate the impact of direct, ultrasound lesion-targeted prostate biopsy, alone or in combination with systematic sampling, on prostate cancer risk prediction.

MATERIALS AND METHODS

We reviewed biopsy findings for men with known or clinical suspicion of prostate cancer undergoing direct, ultrasound-targeted biopsy of radiographic lesions with concomitant systematic extended peripheral zone biopsy. We examined the resulting tumor volume estimates, Gleason grade, and Cancer of the Prostate Risk Assessment score generated from each strategy. Resulting multivariate clinical models of adverse surgical pathology-defined as high grade (Gleason pattern, ≥ 4+3) or non-organ-confined disease (≥ pT3a) were compared by the area under the Receiver Operating Characteristic curve.

RESULTS

A total of 352 patients received ultrasound-targeted biopsy. At diagnosis, the mean age was 63 years, median prostate-specific antigen, 5.7 ng/mL (interquartile range, 4.3-8.2), and median 15 cores (interquartile range, 12-18). The addition of targeted cores to systematic biopsy resulted in reclassification of 52 patients (14.7%) based on Gleason score, 45 (12.8%) by percentage of cores involved > 33%, and 51 (14.5%) by single core positivity > 50%; Cancer of the Prostate Risk Assessment risk category increased in 44 (12.5%). In multivariable logistic regression models of 196 men treated with prostatectomy, the area under the Receiver Operating Characteristic curve for the prediction of adverse pathology generated from targeted (0.754), systematic (0.753), and combined approaches (0.763) were not significantly different (P = .831).

CONCLUSIONS

The validity of clinical risk prediction assessed with a multi-variable instrument was maintained in the setting of lesion-targeted biopsy.