The impact of prognostic group classification on prostate cancer progression in intermediate-risk patients according to the European Association of Urology system: results in 479 patients treated with robot-assisted radical prostatectomy at a single tertiary referral center

Background

Treatment outcomes in intermediate-risk prostate cancer (PCa) may be impaired by adverse pathology misclassification including tumor upgrading and upstaging. Clinical predictors of disease progression need to be improved in this category of patients.

Objectives

To identify PCa prognostic factors to define prognostic groups in intermediate-risk patients treated with robot-assisted radical prostatectomy (RARP).

Design

Data from 1143 patients undergoing RARP from January 2013 to October 2020 were collected: 901 subjects had available follow-up, of whom 479 were at intermediate risk.

Methods

PCa progression was defined as biochemical recurrence and/or local recurrence and/or distant metastases. Study endpoints were evaluated by statistical methods including Cox's proportional hazards, Kaplan-Meyer survival curves, and binomial and multinomial logistic regression models.

Results

After a median (interquartile range) of 35 months (15-57 months), 84 patients (17.5%) had disease progression, which was independently predicted by the percentage of biopsy-positive cores ⩾ 50% and the International Society of Urological Pathology (ISUP) grade group 3 for clinical factors and by ISUP > 2, positive surgical margins and pelvic lymph node invasion for pathological features. Patients were classified into clinical and pathological groups as favorable, unfavorable (one prognostic factor), and adverse (more than one prognostic factor). The risk of PCa progression increased with worsening prognosis through groups. A significant positive association was found between the two groups; consequently, as clinical prognosis worsened, the risk of detecting unfavorable and adverse pathological prognostic clusters increased in both unadjusted and adjusted models.

Conclusion

The study identified factors predicting disease progression that allowed the computation of highly correlated prognostic groups. As the prognosis worsened, the risk of PCa progression increased. Intermediate-risk PCa needs more prognostic stratification for appropriate management.

Intensity-modulated radiation therapy for intermediate-risk prostate cancer: does ADT still have an impact in the dose-escalated external beam radiation therapy era?

BACKGROUND

This study aimed to investigate the effect of androgen deprivation therapy (ADT) on the survival of intermediate-risk prostate cancer (IR-PCA) patients treated with dose-escalated external beam radiation therapy (DE-EBRT), and to determine the group that will benefit from ADT.

METHODS

We analysed 620 IR-PCA patients treated with DE-EBRT at two institutions. Variables were adjusted using the stabilised inverse probability of treatment weighting method (sIPTW) between radiation therapy (RT) and RT plus ADT groups. Biochemical relapse-free survival (bRFS) rate and overall survival (OS) rate were compared using Kaplan-Meier analysis and log-rank test. Cox proportional hazard analysis (CPH) was conducted to detect unfavorable risk factors.

RESULTS

This study included 405 patients; with 217 and 188 patients in the RT and RT plus ADT groups, respectively. The prescribed radiation dose was 78 Gy in 39 fractions. The median follow-up time was 82.0 months. After sIPTW-adjustment, 214.3 and 189.7 patients were assigned to the RT and RT plus ADT groups, respectively. The 7-year bRFS and OS were 89.3% and 94.6% in RT group and 92.3% and 91.0% in RT plus ADT group, respectively. Before and after sIPTW adjustment, no statistically significant differences were found in these endpoints between treatment groups. Multivariate CPH for bRFS revealed Gleason score (GS) 4 + 3 as an unfavorable risk factor, and ADT improved biochemical control of them.

CONCLUSION

ADT may not always be effective in all Japanese IR-PCA patients treated with DE-EBRT, but it can improve biochemical control in patients with GS 4 + 3.

Hypofractionated Radiotherapy in Intermediate-Risk Prostate Cancer Patients: Long-Term Results

Background: To evaluate outcomes in terms of survival and toxicity in a series of intermediate-risk prostate cancer (PCa) patients treated with hypofractionated radiotherapy (HyRT) + hormonal therapy (HT) with or without image guidance (IGRT) and to investigate the impact of different variables. Methods: This is a multi-centric study. From January 2005 to December 2019, we treated 313 intermediate-risk PCa patients (T2b−T2c, Gleason score 7, or pre-treatment PSA 10 to 20 ng/mL) with HyRT. Patients received 54.75 Gy in 15 fractions in 5 weeks plus 9 months of neo-adjuvant, concomitant, and adjuvant HT with or without IGRT. Results: Median follow-up was 91.6 months (range 5.1−167.8 months). Median OS was not reached, and the 8- and 10-year OS was 81.9% and 72.4%, respectively. Median CSS was not reached, and the 8- and 10-year CSS was 97.9% and 94.5%, respectively. PSA at first follow-up <0.8 ng/mL was significantly related to better oncological outcomes (CSS, bRFS, LRFS, cPFS, and MFS) in both univariate and multivariate analysis. After Propensity Score matching, grade 2−3 acute and cumulative late GU (p = 0.153 and p = 0.581, respectively) and GI (p = 0.196 and p = 0.925, respectively) toxicity were not statistically different in patients treated with or without IGRT. Conclusions: HyRT is effective and safe regardless of the use of IGRT. PSA at first follow-up is an easily accessible prognostic factor that may help the clinicians to identify patients who require a treatment intensification.

The Impact of Gleason Grade 3 as a Predictive Factor for Biochemical Recurrence after Robot-Assisted Radical Prostatectomy: A Retrospective Multicenter Cohort Study in Japan (The MSUG94 Group)

Background and Objectives: This study’s objective was to examine patients treated with robot-assisted radical prostatectomy (RARP) for intermediate-risk prostate cancer (IR-PCa), and to identify preoperative risk factors for biochemical recurrence (BCR) in these patients in Japan. Materials and Methods: We conducted a retrospective multicenter cohort study of patients with PCa who underwent RARP at 10 institutions in Japan. A total of 3195 patients were enrolled in this study. We focused on patients with IR-PCa who underwent RARP. We obtained data on pre- and postoperative covariates from the enrolled patients. Biochemical recurrence-free survival was the primary endpoint of this study. We also identified useful preoperative predictive factors for BCR in patients with IR-PCa after RARP. Results: A total of 1144 patients with IR-PCa were enrolled in this study. The median follow-up period was 23.7 months. At the end of the follow-up period, 94 (8.2%) patients developed BCR. The 2 and 3 year biochemical recurrence-free survival (BRFS) rates were 92.2% and 90.2%, respectively. Using the Kaplan–Meier method, Gleason grade (GG) 3 was significantly associated with poor BRFS compared with ≤GG 2. In multivariate analysis, GG 3 was a significant predictive factor for BCR in patients with IR-PCa. Conclusions: The results of the study indicated a significant relationship between GG 3 and post-RARP BCR in patients with IR-PCa.

Effect of Radiation Treatment at a High-Volume Center on Outcomes in Intermediate-Risk Prostate Cancer: An Analysis of the National Cancer Database

OBJECTIVE

To investigate the effect of radiation treatment at a high-volume center on overall survival in men with intermediate-risk prostate cancer.

METHODS

From 2004-2015, 430,347 patients with intermediate-risk prostate cancer were identified in the NCDB. Radiation case volume (RCV) of each hospital was calculated based on number of patients treated. After excluding certain patients including those with metastatic disease, our final analysis population included 116,091 intermediate-risk prostate cancer patients receiving radiation therapy (RT) or radiation with androgen deprivation therapy (RT+ADT). Characteristics analyzed include age, race, distance to treatment facility, Charlson-Deyo Score (CDS), and socioeconomic factors. Primary outcome was overall survival (OS). 5-year survival rates were estimated using the Kaplan-Meier method. Adjusted hazard ratios (HR) with 95% confidence intervals (CI) were computed using multivariate analysis (MVA). Cox regression and propensity score-matched (PSM) analysis was performed.

RESULTS

Median follow up was 63.5 months and estimated 5-year OS was 90.1% at high RCV centers and 88.2% at low RCV centers (p<0.0001). Treatment at high RCV facility was associated with significantly lower mortality compared to treatment at a low RCV facility on MVA and PSM analysis. The survival benefit of treatment at a high RCV facility remained when high RCV facilities were defined as those above the 80^th, 90^th, and 95^th percentile in patient volume (p<0.05).

CONCLUSIONS

Treatment at a high radiation case volume facility is associated with improved OS in patients with radiation-treated intermediate-risk prostate cancer. This survival benefit is important to consider when choosing a treatment center for radiation therapy.

Active surveillance for intermediate-risk prostate cancer in African American and non-Hispanic White men

BACKGROUND

The safety of active surveillance (AS) for African American men compared with non-Hispanic White (White) men with intermediate-risk prostate cancer is unclear.

METHODS

The authors identified patients with modified National Comprehensive Cancer Network favorable ("low-intermediate") and unfavorable ("high-intermediate") intermediate-risk prostate cancer diagnosed between 2001 and 2015 and initially managed with AS in the Veterans Health Administration database. They analyzed definitive treatment, disease progression, metastases, prostate cancer-specific mortality (PCSM), and all-cause mortality by using cumulative incidences and multivariable competing-risks (disease progression, metastasis, and PCSM) or Cox (all-cause mortality) regression.

RESULTS

The cohort included 1007 men (African Americans, 330 [32.8%]; Whites, 677 [67.2%]) followed for a median of 7.7 years; 773 (76.8%) had low-intermediate-risk disease, and 234 (23.2%) had high-intermediate-risk disease. The 10-year cumulative incidences of definitive treatment were not significantly different (African Americans, 83.5%; 95% confidence interval [CI], 78.5%-88.7%; Whites, 80.6%; 95% CI, 76.6%-84.4%; P = .17). Among those with low-intermediate-risk disease, there were no significant differences in the 10-year cumulative incidences of disease progression (African Americans, 46.8%; 95% CI, 40.0%-53.3%; Whites, 46.9%; 95% CI, 42.1%-51.5%; P = .91), metastasis (African Americans, 7.1%; 95% CI, 3.7%-11.8%; Whites, 10.8%; 95% CI, 7.6%-14.6%; P = .17), or PCSM (African Americans, 3.8%; 95% CI, 1.6%-7.5%; Whites, 3.8%; 95% CI, 2.0%-6.3%; P = .69). In a multivariable regression including the entire cohort, African American race was not associated with increased risks of definitive treatment, disease progression, metastasis, PCSM, or all-cause mortality (all P > .30).

CONCLUSIONS

Outcomes in the Veterans Affairs Health System were similar for African American and White men treated for low-intermediate-risk prostate cancer with AS.

Cost-Utility Analysis of Radiation Treatment Modalities for Intermediate-Risk Prostate Cancer

INTRODUCTION

Variable costs of different radiation treatment modalities have played an important factor in selecting the most appropriate treatment for patients with intermediate-risk prostate cancer.

METHODS

Analysis using a Markov model was conducted to simulate 20-year disease trajectory, quality-adjusted life years (QALYs) and health system costs of a cohort of intermediate-risk prostate cancer patients with mean age of 60 years. Clinical outcomes on toxicity and disease recurrence were measured and a probabilistic sensitivity analysis was performed, varying input parameters simultaneously according to their distributions.

RESULTS

Among the six radiation treatment modalities, including conventionally fractionated intensity-modulated radiation therapy (IMRT), hypofractionated IMRT, IMRT combined with high-dose-rate (HDR) brachytherapy, HDR brachytherapy monotherapy, low-dose-rate brachytherapy monotherapy, and stereotactic body radiotherapy (SBRT), SBRT was found to be more cost-effective when compared with LDR-b and other treatment modalities, resulting in an incremental cost-utility ratio of $2985 per QALY.

CONCLUSIONS

Stereotactic body radiotherapy is the most cost-effective radiation treatment modality in treatment of intermediate-risk prostate cancer, while treatment toxicity and cost data are the key drivers of the cost-utility. Further work is required with long-term follow-up for SBRT.

Risk of cardiovascular mortality with androgen deprivation therapy in prostate cancer: A secondary analysis of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Randomized Controlled Trial

BACKGROUND

For men with radiation-managed prostate cancer, there is conflicting evidence regarding the association between androgen deprivation therapy (ADT) and cardiovascular mortality (CVM), particularly among those who have with preexisting comorbidities. The objective of this study was to analyze the association between ADT and CVM across patient comorbidity status using prospectively collected data from a large clinical trial.

METHODS

In total, 1463 men were identified who were diagnosed with clinically localized, intermediate-risk/high-risk prostate cancer (T2b-T4, Gleason 7-10, or prostate-specific antigen >10 ng/mL) from 1993 to 2001 and managed with either radiation therapy (RT) alone or RT plus ADT during the randomized Prostate, Lung, Colon, and Ovarian (PLCO) Cancer Screening Trial. Adjusted hazard ratios (aHRs) for cause-specific mortality (prostate cancer-specific mortality vs other-cause mortality-including the primary end point of CVM [death from ischemic heart disease, cerebrovascular accident, or other circulatory disease]) were determined using Fine and Gray competing-risk regression analysis and stratified by comorbidity history.

RESULTS

There was no difference in the risk of 5-year CVM between ADT plus RT and RT alone (2.3% vs 3.3%, respectively; aHR, 0.69; 95% CI, 0.38-1.24; P = .21) overall or on subgroup analysis among men with a history of ≥1 preexisting comorbidities (3.2% vs 5.3%, respectively; aHR, 0.83; 95% CI, 0.43-1.60; P = .58), ≥2 preexisting comorbidities (6.9% vs 8.3%, respectively; aHR, 0.95; 95% CI, 0.40-2.25; P = .90), or cardiovascular disease/risk factors (3.6% vs 4.3%, respectively; aHR, 0.85; 95% CI, 0.44-1.65; P = .63). These results were all similar when each component of CVM was analyzed separately-either cardiac, stroke, or other vascular mortality (P > .05).

CONCLUSIONS

This study provides prospectively collected evidence that the use of ADT plus RT, compared with RT alone, is not associated with an increased risk of CVM, even among subgroups of men who have preexisting comorbidities and cardiovascular disease.

External validation of a nomogram for identification of pathologically favorable disease in intermediate risk prostate cancer patients

OBJECTIVE

To establish an external validation of the new nomogram from Gandaglia et al which provides estimates of the probability of pathological favorable disease in pre-operatively defined intermediate-risk PCa.

PATIENTS AND METHODS

Overall, 2928 intermediate-risk PCa patients according to the D'Amico classification undergoing RP and bilateral lymph node dissection in seven academic centres between 2000 and 2011. Pathologically favorable PCa was defined as low-grade organ-confined disease. The Receiver Operating Characteristic (ROC) curve was obtained to quantify the overall accuracy (Area Under the Curve, AUC) of the model to predict specimen-confined (SC) disease. Calibration curve was then constructed to illustrate the relationship between the risk-estimates obtained by the model and the observed proportion of SC disease. Kaplan-Meier method was used for PSA recurrence-free survival (PSA-RFS) assessment.

RESULTS

Median age was 68 years. 10.6% patients finally presented pathologically favorable disease characteristics at RP. A higher PSAD (OR = 0.01; 95%CI = 0.00-0.04; P < 0.0001) and percentage of positive cores (OR = 0.97; 95%CI = 0.96-0.98; P < 0.0001) were associated with a reduced probability of favorable disease at RP in multivariate analysis. ROC curve analysis showed strongest accuracy of the model (AUC = 0.82; 95%CI = 0.79-0.84). Favorable PCa had a significantly better PSA recurrence-free survival rates as compared to unfavorable PCa after RP (94.2% vs 74.4% at 4 years, P < 0.0001).

CONCLUSIONS

This external validation of the Gandaglia nomogram shows relevant accuracy with one out of ten patients in this intermediate risk PCa group with pathologically proven organ-confined disease. This validated risk calculator can help physician to distinguish favorable intermediate risk PCa that can be treated by conservative approach or safer nerve-sparing surgery.