The effect of race on the discriminatory accuracy of models to predict biochemical recurrence after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital and Duke Prostate Center databases

Model risk scores may underestimate rate of biochemical recurrence in African American men with localized prostate cancer: a cohort analysis of over 3000 men

INTRODUCTION

This study aims to determine if there is a difference in prostate cancer nomogram-adjusted risk of biochemical recurrence (BCR) and/or adverse pathology (AP) between African American (AAM) and Caucasian men (CM) undergoing radical prostatectomy (RP).

METHODS

A retrospective review was performed of men undergoing RP in the Pennsylvania Urologic Regional Collaborative between 2015 and 2021. Cox proportional hazard regression models were used to compare the rate of BCR after RP, and logistic regression models were used to compare rates of AP after RP between CM and AAM, adjusting for the CAPRA, CAPRA-S, and MSKCC pre- and post-operative nomogram scores.

RESULTS

Rates of BCR and AP after RP were analyzed from 3190 and 5029 men meeting inclusion criteria, respectively. The 2-year BCR-free survival was lower in AAM (72.5%) compared to CM (79.0%), with a hazard ratio (HR) of 1.38 (95% CI 1.16-1.63, p < 0.001). The rate of BCR was significantly greater in AAM compared to CM after adjustment for MSKCC pre-op (HR 1.29; 95% CI 1.08-1.53; p = 0.004), and post-op nomograms (HR 1.26; 95% CI 1.05-1.49; p < 0.001). There was a trend toward higher BCR rates among AAM after adjustment for CAPRA (HR 1.13; 95% CI 0.95-1.35; p = 0.17) and CAPRA-S nomograms (HR 1.11; 95% 0.93-1.32; p = 0.25), which did not reach statistical significance. The rate of AP was significantly greater in AAM compared to CM after adjusting for CAPRA (OR 1.28; 95% CI 1.10-1.50; p = 0.001) and MSKCC nomograms (OR 1.23; 95% CI 1.06-1.43; p = 0.007).

CONCLUSION

This analysis of a large multicenter cohort provides further evidence that AAM may have higher rates of BCR and AP after RP than is predicted by CAPRA and MSKCC nomograms. Accordingly, AAM may benefit with closer post-operative surveillance and may be more likely to require salvage therapies.

Establishment and Validation of a Novel Prediction Model for Early Natural Biochemical Recurrence After Radical Prostatectomy Based on Post-Operative PSA at Sixth Week

Objective

Based on post-operative PSA at 6th week (PSA_6w) after radical prostatectomy to establish an optimal model for predicting natural biochemical recurrence (BCR).

Methods

A total of 742 patients with post-operative PSA_6w from PC-follow database, between January 2003 and October 2022, were included. All the patients had not received any hormone therapy and radiotherapy before operation and BCR. Of these patients, 588 cases operated by one surgeon were enrolled for modelling and another 154 cases operated by other surgeons were for external validation. After screened by Cox regression, the post-operative PSA_6w, pathological stage, Gleason Grade and positive surgical margins were adopted for modelling. The R software was used to plot the nomogram of the prediction model for BCR. C-index and calibration curve were calculated to evaluate the new model. Finally, integrated discrimination improvement was adopted to evaluate the prediction performances of the new nomogram model and the classical Kattan nomogram.

Results

The C-index of the new model was 0.871 (95% CI: 0.830-0.912). The calibration curve of the new model demonstrated superior consistency between the predicted and actual value. The C-index of the external validation group was 0.850 (95% CI: 0.742-0.958), which demonstrated perfect universality. The integrated discrimination improvement showed a 12.61% improvement in prediction performance over that of the classical Kattan nomogram (P < 0.01). Based on the new nomogram, patients were divided to high and low BCR group with a 3 year BCR-free cutoff probability as 74.72%. Low-risk patients, accounting for 77.89% of the patients, have no need to follow up frequently with a false-negative rate only 5.24%, which will save medical resources to a large extent.

Conclusion

Post-operative PSA6w is a sensitive risk biomarker for early natural BCR. The new nomogram model could predict BCR probability with a higher accuracy and will further simplify the clinical follow-up strategies.

Prostate Cancer Lesions by Zone and Race: Does Multiparametric MRI Demonstrate Racial Difference in Prostate Cancer Lesions for African American Men?

African American (AA) men have increased risk of prostate cancer diagnosis and mortality, but the cause remains unknown. MRI fusion improves diagnosis of localized prostate cancer, particularly in anterior lesions; however, cost and access are limited in a community practice setting. By utilizing a diverse cohort of veterans with equal access to care in a single payer system, we describe prostate cancer detection. We queried a prospectively maintained institutional review board-approved database of men undergoing prostate biopsy for untreated prostate cancer. We included all consecutive patients from October 2017 to February 2020. Statistical analysis including Kaplan–Meier Curves, Fisher’s exact test, and Forest plot was performed. From 246 consecutive patients, 166 were AA and 80 were non-AA. There were similar distributions of PSA, PSAD, and number of targetable lesions between the AA and non-AA cohort (p > 0.05 for all). We found no difference in location on MRI between race groups. There was similar cancer detection, focusing on anterior lesions and rate of positive Gleason grade (≥GG1) and clinically significant (≥GG2) cancer between cohorts. In a predominant AA cohort of veterans, we found similar distribution of location for MRI-targeted lesions, along with rates of tumor detection and aggressiveness of disease. In this single payer veteran population, we did not identify specific biologic differences inherent to tumor detection between AA and non-AA patients.

Genome-wide detection of allelic genetic variation to predict biochemical recurrence after radical prostatectomy among prostate cancer patients using an exome SNP chip

PURPOSES

Genetic variations among prostate cancer patients who underwent radical prostatectomies were evaluated to predict biochemical recurrence, and used to develop a clinical-genetic model that combines data on clinicopathological factors of prostate cancer and individual genetic variations.

MATERIALS AND METHODS

We genotyped 242,186 SNPs on a custom HumanExome BeadChip v1.0 (Illuminam Inc.) from the blood DNA of 776 PCa patients who underwent radical prostatectomy. Genetic data were analyzed to calculate an odds ratio as an estimate of the relative risk of biochemical recurrence. And we compared accuracies from the multivariate model incorporating clinicopathological factors between included and excluded selected lead single nucleotide polymorphisms. Biochemical recurrence-free survival outcomes also analyzed using these genetic variations.

RESULTS

Genetic array analysis indicated that eight single nucleotide polymorphisms (rs77080351, rs200944490, rs2071292, rs117237810, rs191118242, rs4965121, rs61742396, and rs6573513) were significant to predict biochemical recurrence after radical prostatectomy. When a multivariate model incorporating clinicopathological factors was devised to predict biochemical recurrence, the predictive accuracy of model was 85.1 %. By adding in two individual variations of single nucleotide polymorphisms in the multivariate model, the predictive accuracy increased to 87.7 % (P = 0.045). With three variations of single nucleotide polymorphisms, the predictive accuracy further improved to 89.0 % (P = 0.025). These genetic variations had a significantly decreased biochemical recurrence-free survival rate.

CONCLUSIONS

Based on exome array, the selected single nucleotide polymorphisms were predictors for biochemical recurrence. The addition of individualized genetic information effectively enhanced the predictive accuracy of biochemical recurrence among prostate cancer patients who underwent radical prostatectomy.

African-american race is a predictor of seminal vesicle invasion after radical prostatectomy

INTRODUCTION

The purpose of the study was to determine whether racial differences exist in the pattern of local disease progression among men treated with radical prostatectomy (RP) for localized prostate cancer (PCa), which is currently unknown. In this study we evaluated the pattern of adverse pathologic features in an identical cohort of African-American (AA) and Caucasian (CS) men with PCa.

PATIENTS AND METHODS

The overall cohort consisted of 1104 men (224 AA, and 880 CS) who underwent RP between 1990 and 2012. We compared preoperative factors and pathologic outcomes after RP across race groups. Multivariate analysis was used to identify factors predictive of adverse pathologic outcomes. The effect of race on adverse pathologic outcomes and biochemical control rate (BCR) was evaluated using multivariate regression model and Kaplan-Meier analysis.

RESULTS

The 10-year BCR was 59% versus 82% in AA and CS men, respectively (P = .003). There was no significant difference in extraprostatic spread (P = .14), positive surgical margin (P = .81), lymph node involvement (P = .71), or adverse pathologic features (P = .16) across race groups. However, among patients with ≥ 1 adverse pathologic features, AA men had higher rate of seminal vesicle invasion (SVI) compared with CS men (51% vs. 30%; P = .01). After adjusting for known predictors of adverse pathologic features AA race remained a predictor of SVI.

CONCLUSION

AA men have an increased risk of SVI after RP, particularly among men with Gleason ≤ 6 disease. This might represent racial differences in the biology of PCa disease progression, which contribute to poorer outcomes in AA men.

African American men with low-grade prostate cancer have increased disease recurrence after prostatectomy compared with Caucasian men

PURPOSE

To explore whether disparities in outcomes exist between African American (AA) and Caucasian (CS) men with low-grade prostate cancer and similar cancer of the prostate risk assessment-postsurgery (CAPRA-S) features following prostatectomy (RP).

METHODS

The overall cohort consisted of 1,265 men (234 AA and 1,031 CS) who met the National comprehensive cancer network criteria for low- to intermediate-risk prostate cancer and underwent RP between 1990 and 2012. We first evaluated whether clinical factors were associated with adverse pathologic outcomes and freedom from biochemical failure (FFbF) using the entire cohort. Next, we studied a subset of 705 men (112 AA and 593 CS) who had pathologic Gleason score≤6 (low-grade disease). Using this cohort, we determined whether race affected FFbF in men with RP-proven low-grade disease and similar CAPRA-S scores.

RESULTS

With a median follow-up time of 27 months, the overall 7-year FFbF rate was 86% vs. 79% in CS and AA men, respectively (P = 0.035). There was no significant difference in one or more adverse pathologic features between CS vs. AA men (27% vs. 31%; P = 0.35) or CAPRA-S score (P = 0.28). In the subset analysis of patients with low-grade disease, AA race was associated with worse FFbF outcomes (P = 0.002). Furthermore, AA race was a significant predictor of FFbF in men with low-grade disease (hazard ratio = 2.01, 95% CI: 1.08-3.72; P = 0.029).

CONCLUSIONS

AA race is a predictor of worse FFbF outcomes in men with low-grade disease after RP. These results suggest that a subset of AA men with low-grade disease may benefit from more aggressive treatment.

African American men with very low-risk prostate cancer exhibit adverse oncologic outcomes after radical prostatectomy: should active surveillance still be an option for them?

PURPOSE

Active surveillance (AS) is a treatment option for men with very low-risk prostate cancer (PCa); however, favorable outcomes achieved for men in AS are based on cohorts that under-represent African American (AA) men. To explore whether race-based health disparities exist among men with very low-risk PCa, we evaluated oncologic outcomes of AA men with very low-risk PCa who were candidates for AS but elected to undergo radical prostatectomy (RP).

PATIENTS AND METHODS

We studied 1,801 men (256 AA, 1,473 white men, and 72 others) who met National Comprehensive Cancer Network criteria for very low-risk PCa and underwent RP. Presenting characteristics, pathologic data, and cancer recurrence were compared among the groups. Multivariable modeling was performed to assess the association of race with upgrading and adverse pathologic features.

RESULTS

AA men with very low-risk PCa had more adverse pathologic features at RP and poorer oncologic outcomes. AA men were more likely to experience disease upgrading at prostatectomy (27.3% v 14.4%; P < .001), positive surgical margins (9.8% v 5.9%; P = .02), and higher Cancer of the Prostate Risk Assessment Post-Surgical scoring system (CAPRA-S) scores. On multivariable analysis, AA race was an independent predictor of adverse pathologic features (odds ratio, [OR], 3.23; P = .03) and pathologic upgrading (OR, 2.26; P = .03).

CONCLUSION

AA men with very low-risk PCa who meet criteria for AS but undergo immediate surgery experience significantly higher rates of upgrading and adverse pathology than do white men and men of other races. AA men with very low-risk PCa should be counseled about increased oncologic risk when deciding among their disease management options.

Obesity, prostate-specific antigen nadir, and biochemical recurrence after radical prostatectomy: biology or technique? Results from the SEARCH database

BACKGROUND

Obesity is associated with an increased risk of biochemical recurrence (BCR) after radical prostatectomy (RP). It is unclear whether this is due to technical challenges related to operating on obese men or other biologic factors.

OBJECTIVE

To examine whether obesity predicts higher prostate-specific antigen (PSA) nadir (as a measure of residual PSA-producing tissue) after RP and if this accounts for the greater BCR risk in obese men.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of 1038 RP patients from 2001 to 2010 in the multicenter US Veterans Administration-based Shared Equal Access Regional Cancer Hospital database with median follow-up of 41 mo.

INTERVENTION

All patients underwent RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We evaluated the relationship between body mass index (BMI) and ultrasensitive PSA nadir within 6 mo after RP. Adjusted proportional hazards models were used to examine the association between BMI and BCR with and without PSA nadir.

RESULTS AND LIMITATIONS

Mean BMI was 28.5 kg/m2. Higher BMI was associated with higher PSA nadir on both univariable (p=0.001) and multivariable analyses (p<0.001). Increased BMI was associated with increased BCR risk (hazard ratio [HR]: 1.06; p=0.007). Adjusting for PSA nadir slightly attenuated, but did not eliminate, this association (HR: 1.04, p=0.043). When stratified by PSA nadir, obesity only significantly predicted BCR in men with an undetectable nadir (p=0.006). Unfortunately, other clinically relevant end points such as metastasis or mortality were not available.

CONCLUSIONS

Obese men are more likely to have a higher PSA nadir, suggesting that either more advanced disease or technical issues confound an ideal operation. However, even after adjusting for the increased PSA nadir, obesity remained predictive of BCR, suggesting that tumors in obese men are growing faster. This provides further support for the idea that obesity is biologically associated with prostate cancer progression.

Impact of race on biochemical disease recurrence after prostate brachytherapy

BACKGROUND

Understanding racial differences in disease presentation and response to therapy is necessary for the effective treatment and control of prostate cancer. In this study, the authors examined the influence of race on biochemical disease-free survival (BDFS) among men who received prostate brachytherapy.

METHODS

In total, 2301 men were identified who had a minimum follow-up of 24 months and had received low-dose-rate brachytherapy for prostate cancer at the Mount Sinai Medical Center from June 1990 to October 2008. Patient factors, with specific emphasis on patient race, were analyzed with respect to freedom from biochemical failure (FFbF). Kaplan-Meier analyses, life-tables, and log-rank tests were used to identify variables that were predictive of 10-year FFbF.

RESULTS

In this series, a total of 2268 patients included 81% Caucasians, 12% African Americans, 6% Hispanics, and 1% Asians. The 10-year actuarial FFbF rate was 70% for AA men and 84% for all others (P = .002). Between Caucasian men and AA men, the 10-year FFbF rate was 83% versus 70%, respectively (P = .001).There was no significant difference in 10-year FFbF between Caucasian men and Hispanic men (83% vs 86%, respectively; P = .6). The 10-year FFbF rate for Hispanic men and AA men was 86% versus 70%, respectively (P = .062). A greater percentage of AA men presented with higher prostate-specific antigen levels (PSA) (>10 ng/mL; 44% vs 21%; P < .001) and, thus, with higher risk disease (24% vs 15%; P < .001) compared with Caucasian men. Among the men with low-risk disease, the 10-year FFbF rate was 90% for Caucasian men and 76% for AA men (P = .041). The 10-year BDFS rate for patients who received brachytherapy alone was 86% for Caucasian men and 61% for AA men (P = .001); however, this difference was not observed when brachytherapy was combined with androgen-deprivation therapy(ADT) with or without supplemental external-beam radiotherapy (EBRT). Multivariate analysis revealed that PSA (P = .024), Gleason score (P < .001), the biologic effective dose (P < .001), EBRT (P = .002), ADT (P = .03), and AA race (P = .037) were significant predictors of 10-year FFbF. No significant differences was observed in overall survival, cause-specific survival, or distant metastasis-free survival between racial groups.

CONCLUSIONS

AA race appeared to be an independent negative predictor of BDFS after prostate brachytherapy, and this result may highlight the need for more aggressive therapy in this patient population.