Predicting pathological outcomes in patients undergoing robot-assisted radical prostatectomy for high-risk prostate cancer: a preoperative nomogram

External Tertiary-Care-Hospital Validation of the Epidemiological SEER-Based Nomogram Predicting Downgrading in High-Risk Prostate Cancer Patients Treated with Radical Prostatectomy

We aimed to externally validate the SEER-based nomogram used to predict downgrading in biopsied high-risk prostate cancer patients treated with radical prostatectomy (RP) in a contemporary European tertiary-care-hospital cohort. We relied on an institutional tertiary-care database to identify biopsied high-risk prostate cancer patients in the National Comprehensive Cancer Network (NCCN) who underwent RP between January 2014 and December 2022. The model's downgrading performance was evaluated using accuracy and calibration. The net benefit of the nomogram was tested with decision-curve analyses. Overall, 241 biopsied high-risk prostate cancer patients were identified. In total, 51% were downgraded at RP. Moreover, of the 99 patients with a biopsy Gleason pattern of 5, 43% were significantly downgraded to RP Gleason pattern ≤ 4 + 4. The nomogram predicted the downgrading with 72% accuracy. A high level of agreement between the predicted and observed downgrading rates was observed. In the prediction of significant downgrading from a biopsy Gleason pattern of 5 to a RP Gleason pattern ≤ 4 + 4, the accuracy was 71%. Deviations from the ideal predictions were noted for predicted probabilities between 30% and 50%, where the nomogram overestimated the observed rate of significant downgrading. This external validation of the SEER-based nomogram confirmed its ability to predict the downgrading of biopsy high-risk prostate cancer patients and its accurate use for patient counseling in high-volume RP centers.

Nomogram Predicting Downgrading in National Comprehensive Cancer Network High-risk Prostate Cancer Patients Treated with Radical Prostatectomy

BACKGROUND

Some high-risk prostate cancer (PCa) patients may show more favorable Gleason pattern at radical prostatectomy (RP) than at biopsy.

OBJECTIVE

To test whether downgrading could be predicted accurately.

DESIGN, SETTING, AND PARTICIPANTS

Within the Surveillance, Epidemiology and End Results database (2010-2016), 6690 National Comprehensive Cancer Network (NCCN) high-risk PCa patients were identified.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

We randomly split the overall cohort between development and validation cohorts (both n = 3345, 50%). Multivariable logistic regression models used biopsy Gleason, prostate-specific antigen, number of positive prostate biopsy cores, and cT stage to predict downgrading. Accuracy, calibration, and decision curve analysis (DCA) tested the model in the external validation cohort.

RESULTS AND LIMITATIONS

Of 6690 patients, 50.3% were downgraded at RP, and of 2315 patients with any biopsy pattern 5, 44.1% were downgraded to RP Gleason pattern ≤4 + 4. Downgrading rates were highest in biopsy Gleason pattern 5 + 5 (84.1%) and lowest in 3 + 4 (4.0%). In the validation cohort, the logistic regression model-derived nomogram predicted downgrading with 71.0% accuracy, with marginal departures (±3.3%) from ideal predictions in calibration. In DCA, a net benefit throughout all threshold probabilities was recorded, relative to treat-all or treat-none strategies and an algorithm based on an average downgrading rate of 50.3%. All steps were repeated in the subgroup with any biopsy Gleason pattern 5, to predict RP Gleason pattern ≤4 + 4. Here, a second nomogram (n = 2315) yielded 68.0% accuracy, maximal departures from ideal prediction of ±5.7%, and virtually the same DCA pattern as the main nomogram.

CONCLUSIONS

Downgrading affects half of all high-risk PCa patients. Its presence may be predicted accurately and may help with better treatment planning.

PATIENT SUMMARY

Downgrading occurs in every second high-risk prostate cancer patients. The nomograms developed by us can predict these probabilities accurately.

Heterogeneous oncologic outcomes according to surgical pathology in high-risk prostate cancer: implications for better risk stratification and preoperative prediction of oncologic outcomes

PURPOSE

To evaluate the better risk stratification based on surgical pathology, and to predict oncologic outcomes after radical prostatectomy (RP) with a better scoring system in high-risk prostate cancer (PCa) patients.

METHODS

We evaluated high-risk PCa patients (PSA >20 ng/ml, ≥cT3a, or Gleason score 8-10) who underwent RP between 2007 and 2013 at our institute. We classified patients into three groups according to their pathologic outcomes: favorable (pT2, Gleason score ≤7, and node negative), intermediate (specimen-confined disease (pT2-3a, node negative PCa with negative surgical margins) but not in the favorable group), and unfavorable (the remaining patients). We developed a risk stratification scoring system to predict prognostic outcomes after RP and validated our scoring system to estimate its predictive accuracy.

RESULTS

Among a total of 356 patients, 95 (26.7%), 115 (32.3%), and 146 (41%) were in the favorable, intermediate, and unfavorable prognostic groups, respectively. The 5-year biochemical recurrence-free survival rates of the patients in each group were 87.8, 64.6, and 41.4%, respectively. We developed a scoring system based on preoperative PSA, clinical stage, percentage of tumor positive core, and percentage of cores with a Gleason score 8-10. This demonstrated internally and externally validated concordance indices of 0.733 and 0.772, respectively.

CONCLUSIONS

Using our scoring system, we can predict which patients with high-risk PCa would benefit more from RP. Thus, this system can be used in patient counseling to determine an optimal treatment strategy for high-risk PCa.

Significant reduction in positive surgical margin rate after laparoscopic radical prostatectomy by application of the modified surgical margin recommendations of the 2009 International Society of Urological Pathology consensus

OBJECTIVES

To verify retrospectively the margin status and analyse the location and characteristics of positive surgical margins (PSMs) in patients undergoing radical prostatectomy (RP), by a central pathology review, based on the consensus conference 2009 updated margin criteria from the International Society of Urological Pathology (ISUP).

PATIENTS AND METHODS

The detailed PSM characteristics of 441 patients who underwent laparoscopic RP (LRP) between 1999 and 2007 were centrally reviewed with regard to location, number, Gleason score at the PSM and tumour width. Predictors of PSMs and the impact of several PSM characteristics on clinical outcomes were examined. Patient characteristics were compared using the chi-squared test. Differences in recurrence-free survival (RFS) rates were analysed using the log-rank test and presented as Kaplan-Meier survival curves. Univariable and multivariable Cox regression analysis for the prediction of RFS was performed.

RESULTS

Central pathology review using the updated PSM definition according to ISUP 2009, resulted in reclassification of a substantial number of patients with PSMs (n = 113, 26.6%) as R0. Several PSM characteristics with a higher risk of biochemical recurrence (BCR) were identified as the strongest independent predictors of RFS: pathological stage; Gleason score; and the presence of multiple PSMs (hazard ratio [HR] 1.78; 95% confidence interval [CI] 1.08-2.96; P = 0.025). Further analysis replacing the location of PSM by the width categories of PSM showed that a PSM >3 mm was an independent predictor of RFS (HR 1.72; 95% CI 1.08-2.72; P = 0.022).

CONCLUSIONS

The impact of PSMs after LRP for prostate cancer remains unclear. PSMs in the present cohort of patients undergoing LRP had different characteristics and conferred different risks of BCR. A better understanding of PSM characteristics and a careful standardized pathological evaluation is needed to adequately counsel patients with respect to prognosis and adjuvant therapy after LRP.