Impact of Postoperative Radiotherapy in Men with Persistently Elevated Prostate-specific Antigen After Radical Prostatectomy for Prostate Cancer: A Long-term Survival Analysis

Analysis of risk factors for persistent PSA after radical prostatectomy: results from a high-volume center in Southeast China

BACKGROUND

For localized prostate cancer, a comprehensive treatment approach centered around radical prostatectomy (RP) is often their optimal choice. Successful RP can typically reduce prostate-specific antigen (PSA) levels to below 0.1 ng/mL within 6 to 8 weeks postoperatively. However, in clinical practice, 5 to 24% of patients may have a PSA ≥ 0.1 ng/mL at 6 to 8 weeks after surgery, a phenomenon known as PSA persistence. Many studies based on data from Europe and United States have shown an association between PSA persistence and poor postoperative outcomes, further analyzing the risk factors for PSA persistence. However, relevant research based on data from China remains scarce.

METHODS

Retrospective study of 1,347 prostate cancer patients who underwent RP at the First Affiliated Hospital of Zhejiang University School of Medicine from July 15, 2016, to August 31, 2022. Based on inclusion criteria, univariate and multivariate logistic regression analyses were conducted to explore the independent risk factors for persistent PSA.

RESULTS

Among the 826 prostate cancer patients after RP, 124 patients experienced persistent PSA. In univariate logistic regression analysis, robot-assisted laparoscopic radical prostatectomy (RARP), preoperative PSA, high-risk group, preoperative International Society of Urological Pathology (ISUP) grades 2-5, postoperative ISUP grades 3-5, percentage of positive cores, cT3, ≥pT3b, extracapsular extension (EPE), seminal vesicle invasion (SVI), positive surgical margins (PSM) and Prostate Specific Antigen Density (PSAD) were all significantly associated with PSA persistence after RP (P < 0.05). In terms of surgical approach, RARP was considered a protective factor against postoperative PSA persistence (OR:0.53, p < 0.05). In multivariate logistic regression analysis, preoperative ISUP grade 4, percentage of positive cores and PSM were independent risk factors of PSA persistence after RP (P < 0.05).

CONCLUSION

Preoperative PSA, high-risk group, preoperative ISUP grades 2-5, postoperative ISUP grades 3-5, percentage of positive cores, cT3, ≥pT3b, EPE, SVI, PSM and PSAD were independent risk factors for PSA persistence in prostate cancer patients after RP. This provides assistance for early monitoring and treatment of patients at high risk of persistent PSA in clinical practice.

Risk factors for prostate-specific antigen persistence in pT3aN0 prostate cancer after robot-assisted laparoscopic radical prostatectomy: a retrospective study

BACKGROUND

The aim of this study was to evaluate the risk factors for prostate-specific antigen (PSA) persistence in pathological stage T3aN0 prostate cancer (PCa) after robot-assisted laparoscopic radical prostatectomy (RALP).

METHODS

A retrospective study was performed on 326 patients with pT3aN0 PCa who underwent RALP between March 2020 and February 2022. PSA persistence was defined as nadir PSA of >0.1 ng/mL after RALP, and the risk factors for PSA persistence were evaluated using logistic regression analysis.

RESULTS

Among 326 patients, 61 (18.71%) had PSA persistence and 265 (81.29%) had PSA of <0.1 ng/mL after RALP (successful radical prostatectomy [RP] group). In the PSA persistence group, 51 patients (83.61%) received adjuvant treatment. Biochemical recurrence occurred in 27 patients (10.19%) in the successful RP group during the mean follow-up period of 15.22 months. Multivariate analysis showed that the risk factors for PSA persistence were large prostate volume (hazard ratio [HR], 1.017; 95% confidence interval [CI], 1.002-1.036; p=0.046), lymphovascular invasion (LVI) (HR, 2.605; 95% CI, 1.022-6.643; p=0.045), and surgical margin involvement (HR, 2.220; 95% CI, 1.110-4.438; p=0.024).

CONCLUSION

Adjuvant treatment may be needed for improved prognosis in patients with pT3aN0 PCa after RALP with a large prostate size, LVI, or surgical margin involvement.

The Impact of the Percent of Residual Prostate-Specific Antigen on Metastasis-Free Survival in Patients with Persistent Prostate-Specific Antigen after Radical Prostatectomy

PURPOSE

Persistent levels of prostate-specific antigen (PSA) is a poor prognostic factor for recurrence after radical prostatectomy (RP). We investigated the impact of the percentage of residual PSA (%rPSA) [(post-/preoperative PSA)×100], representing a biochemical residual tumor, and the first postoperative PSA (fPSA) level on metastasis-free survival (MFS) in men with persistent levels of PSA after RP.

MATERIALS AND METHODS

We retrospectively identified male patients within a single tertiary referral hospital database who harbored persistent (≥0.1 ng/mL) vs. undetectable (<0.1 ng/mL) PSA levels 4 to 8 weeks after RP. Kaplan-Meier analyses and Cox regression models were used to test the effect of persistent PSA levels, the fPSA level, and %rPSA on MFS.

RESULTS

Of 1,205 patients, 178 patients with persistent PSA levels were enrolled. Seven-year MFS rates were 60.5% vs. 84.3% (p<0.001) for patients with a %rPSA ≥6% and <6%, respectively. Multivariable Cox regression models of the overall cohort revealed that persistent PSA levels (hazard ratio [HR], 3.94; p=0.010), extracapsular extension (HR, 4.17; 95% confidence interval [CI], 1.06-16.41; p=0.041), and pathological Gleason grade group (pGGG) (HR, 3.69; 95% CI, 1.32-10.27; p=0.013) were independent predictors of metastasis. Multivariable Cox regression models in men with persistent PSA levels revealed that the %rPSA (HR, 8.92; 95% CI, 1.74-45.71; p=0.009) and pGGG 4-5 (HR, 4.13; 95% CI, 1.22-13.96; p=0.022) were independent predictors of distant metastasis, but not the fPSA level after surgery.

CONCLUSIONS

Persistent levels of PSA were associated with worse MFS after RP. In men with persistent PSA levels after RP, the %rPSA is a valuable predictor of MFS unlike the fPSA level.

Clinicopathological and oncological significance of persistent prostate-specific antigen after radical prostatectomy: A systematic review and meta-analysis

Objective

To investigate the association of persistently elevated prostate-specific antigen (PSA) after radical prostatectomy (RP) with clinicopathological features and long-term oncological prognosis for the development of a potential management strategy.

Methods

A systematic literature search was performed using PubMed and Web of Science up to June 2021 to identify the eligible studies focusing on understanding the impact of persistent PSA in patients who underwent RP for localized prostate cancer. Meta-analyses were performed on parameters with available information.

Results

A total of 32 RP studies were identified, of which 11 included 26 719 patients with consecutive cohorts and the remaining 21 comprised 24 177 patients with cohorts carrying specific restrictions. Of the 11 studies with consecutive cohorts, the incidence of persistent PSA varied between 3.1% and 34.6% with a median of 11.0%. Meta-analyses revealed patients with persistent PSA consistently showed unfavorable clinicopathological features and a more than 3.5-fold risk of poorer biochemical recurrence, metastasis, and prostate cancer-specific mortality prognosis independently, when compared to patients with undetectable PSA. Similarly, cases with persistent PSA in different specific patient cohorts with a higher risk of prostate cancer also showed a trend of worse outcomes.

Conclusion

We found that the frequency of persistent PSA was about 11.0% in consecutive RP cohorts. Persistent PSA was significantly associated with unfavorable clinicopathological characteristics and worse oncological outcomes. Patients with persistent PSA after RP may benefit from early salvage treatment to delay or prevent biochemical recurrence, improving oncological outcomes for these patients. Further prospective randomized controlled trials are warranted to understand optimal systemic therapy in these patients.

Management of patients with a persistently elevated PSA after radical prostatectomy: a narrative review

INTRODUCTION

The management of the postoperative biological relapse of prostate cancer is most often based on salvage radiotherapy (SRT) with or without the addition of a variable duration of hormone therapy (HT). The indications for SRT +/- HT are established in the setting of a rising PSA level after a period where an undetectable PSA was achieved. However, in case of detectable PSA immediately after radical prostatectomy, the treatment options and prognosis are still unclear.

MATERIALS AND METHODS

We conducted a narrative review based on an analysis of the literature focusing on articles targeting the population of patients with postoperative persistently detectable PSA level. Case reports, original articles, clinical trials, and published reviews were studied for this purpose.

CONCLUSION

This article will describe current management of patients with detectable PSA immediately after radical prostatectomy, notably the contribution of modern imaging and new treatment options involving the combination of RT and HT.

[Salvage radiotherapy after prostatectomy - what do do in case of elevated post operative PSA or macroscopic relapse?]

The management of the postoperative biological relapse of prostate cancer is most often based on salvage radiotherapy (RT) and a variable duration of hormone therapy (HT) in addition. The indications for RT±HT become more consensual for the adjuvant postoperative situation or in the event of a rising PSA level after a period where an undetectable PSA level was achieved. On the other hand, in the event of detectable PSA immediately postoperatively or in the event of a biological recurrence with macroscopic relapse in the prostate bed seen on conventional imaging assessment, the treatment options are still being evaluated. This article will describe these 2 situations and their current management but also will come through assessments with the contribution of modern imaging and new treatment options in terms of RT dose and RT±HT combination.

Benefits of early salvage therapy on oncological outcomes in high-risk prostate cancer with persistent PSA after radical prostatectomy

BACKGROUND

Patients with prostate-specific antigen (PSA) persistence are at the increased risk of disease progression. The aim of our study was to evaluate the impact of early salvage therapy on oncological outcomes in patients with persistent PSA after radical prostatectomy (RP).

METHODS

Within a single tertiary centre database, we identified men with persistent (≥ 0.1 ng/ml) versus undetectable (< 0.1 ng/ml) PSA 4-8 weeks after RP for high-risk prostate cancer (HRPCa). The cumulative incidence function was used to estimate cancer-specific survival (CSS) and clinical progression-free survival (CPFS). The Kaplan-Meier method was used to estimate overall survival (OS). The effects on oncological outcomes of salvage radiotherapy (SRT) ± androgen deprivation therapy (ADT) vs. ADT monotherapy were tested in the subgroup of patients with persistent PSA.

RESULTS

Of 414 consecutive patients who underwent RP for HRPC, 125 (30.2%) had persistent PSA. Estimated 10-year CPFS, CSS and OS for men with persistent vs. undetectable PSA were 63.8% vs. 93.5%, 78.5% vs. 98.3% and 54% vs. 83.2% (all p < 0.0001), respectively. In men with persistent PSA, ADT alone was associated with higher risk (hazard ratio (HR) for worse CSS (HR 3.9, p = 0.005) and OS (HR 4.7, p < 0.0001) but not for CP (HR 1.6, p = 0.2) when compared with SRT ± ADT.

CONCLUSION

In patients who underwent RP for HRPCa, persistent PSA was associated with poor oncological outcomes. Early SRT ± ADT resulted in significantly improved CSS and OS in men with persistent PSA comparing with early androgen deprivation monotherapy.

The Significance of Prostate Specific Antigen Persistence in Prostate Cancer Risk Groups on Long-Term Oncological Outcomes

Simple Summary

The current prostate cancer guidelines recommend performing the first prostate-specific antigen measurement at three months after radical prostatectomy. However, at an earlier measurement, persistence (≥0.1 ng/mL) of this biomarker could be found in up to 30% of cases, depending on the prostate cancer risk factors. Recent reports have demonstrated an increasing interest in prostate-specific antigen persistence as a possible additional predictor of disease progression and cancer-specific survival. However, the data remain scant, with weak evidence. We assessed the relationship between prostate-specific antigen persistence and long-term oncological outcomes within prostate cancer risk groups. We found that persistence of this biomarker could be used as an independent predictor of worse long-term outcomes in high-risk prostate cancer patients, while in intermediate-risk patients, this parameter significantly predicts only biochemical recurrence and has no impact on the outcomes in low-risk patients.

Abstract

Objective: To assess the significance of prostate-specific antigen (PSA) persistence at the first measurement after radical prostatectomy (RP) on long-term outcomes in different prostate cancer risk groups. Methods: Persistent PSA was defined as ≥0.1 ng/mL at 4–8 weeks after RP. Patients were stratified into low-, intermediate- and high-risk groups, according to the preoperative PSA, pathological stage, grade group and lymph nodes status. The ten-year cumulative incidence of biochemical recurrence (BCR), metastases, cancer-specific mortality (CSM) and overall mortality (OM) were calculated in patients with undetectable and persistent PSA in different PCa-risk groups. Multivariate regression analyses depicted the significance of PSA persistence on each study endpoint. Results: Of all 1225 men, in 246 (20.1%), PSA persistence was detected. These men had an increased risk of BCR (hazard ratio (HR) 4.2, p < 0.0001), metastases (HR: 2.7, p = 0.002), CRM (HR: 5.5, p = 0.002) and OM (HR: 1.8, p = 0.01) compared to the men with undetectable PSA. The same significance of PSA persistence on each study endpoint was found in the high-risk group (HR: 2.5 to 6.2, p = 0.02 to p < 0.0001). In the intermediate-risk group, PSA persistence was found as a predictor of BCR (HR: 3.9, p < 0.0001), while, in the low-risk group, PSA persistence was not detected as a significant predictor of outcomes after RP. Conclusions: Persistent PSA could be used as an independent predictor of worse long-term outcomes in high-risk PCa patients, while, in intermediate-risk patients, this parameter significantly predicts only biochemical recurrence and has no impact on the outcomes in low-risk PCa patients.

Comparison of hypofractionation and standard fractionation for post-prostatectomy salvage radiotherapy in patients with persistent PSA: single institution experience

BACKGROUND

Hypofractionated post-prostatectomy radiotherapy is emerging practice, however with no randomized evidence so far to support it's use. Additionally, patients with persistent PSA after prostatectomy may have aggressive disease and respond less well on standard salvage treatment. Herein we report outcomes for conventionally fractionated (CFR) and hypofractionated radiotherapy (HFR) in patients with persistent postprostatectomy PSA who received salvage radiotherapy to prostate bed.

METHODS

Single institution retrospective chart review was performed after Institutional Review Board approval. Between May 2012 and December 2016, 147 patients received salvage postprostatectomy radiotherapy. PSA failure-free and metastasis-free survival were calculated using Kaplan-Meier method. Cox regression analysis was performed to test association of fractionation regimen and other clinical factors with treatment outcomes. Early and late toxicity was assessed using Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0.

RESULTS

Sixty-nine patients who had persistent PSA (≥ 0.1 ng/mL) after prostatectomy were identified. Median follow-up was 67 months (95% CI 58-106 months, range, 8-106 months). Thirty-six patients (52.2%) received CFR, 66 Gy in 33 fractions, 2 Gy per fraction, and 33 patients (47.8%) received HFR, 52.5 Gy in 20 fractions, 2.63 Gy per fraction. Forty-seven (68%) patients received androgen deprivation therapy (ADT). 5-year PSA failure- and metastasis-free survival rate was 56.9% and 76.9%, respectively. Thirty patients (43%) experienced biochemical failure after salvage radiotherapy and 16 patients (23%) experienced metastatic relapse. Nine patients (13%) developed metastatic castration-resistant disease and died of advanced prostate cancer. Median PSA failure-free survival was 72 months (95% CI; 41-72 months), while median metastasis-free survival was not reached. Patients in HFR group were more likely to experience shorter PSA failure-free survival when compared to CFR group (HR 2.2; 95% CI 1.0-4.6, p = 0.04). On univariate analysis, factors significantly associated with PSA failure-free survival were radiotherapy schedule (CFR vs HFR, HR 2.2, 95% CI 1.0-4.6, p = 0.04), first postoperative PSA (HR 1.02, 95% CI 1.0-1.04, p = 0.03), and concomitant ADT (HR 3.3, 95% CI 1.2-8.6, p = 0.02). On multivariate analysis, factors significantly associated with PSA failure-free survival were radiotherapy schedule (HR 3.04, 95% CI 1.37-6.74, p = 0.006) and concomitant ADT (HR 4.41, 95% CI 1.6-12.12, p = 0.004). On univariate analysis, factors significantly associated with metastasis-free survival were the first postoperative PSA (HR 1.07, 95% CI 1.03-1.12, p = 0.002), seminal vesicle involvement (HR 3.48, 95% CI 1.26-9.6,p = 0.02), extracapsular extension (HR 7.02, 95% CI 1.96-25.07, p = 0.003), and surgical margin status (HR 2.86, 95% CI 1.03-7.97, p = 0.04). The first postoperative PSA (HR 1.04, 95% CI 1.00-1.08, p = 0.02) and extracapsular extension (HR 4.24, 95% CI 1.08-16.55, p = 0.04) remained significantly associated with metastasis-free survival on multivariate analysis. Three patients in CFR arm (8%) experienced late genitourinary grade 3 toxicity.

CONCLUSIONS

In our experience, commonly used hypofractionated radiotherapy regimen was associated with lower biochemical control compared to standard fractionation in patients with persistent PSA receiving salvage radiotherapy. Reason for this might be lower biological dose in HFR compared to CFR group. However, this observation is limited due to baseline imbalances in ADT use, ADT duration and Grade Group distribution between two radiotherapy cohorts. In patients with persistent PSA post-prostatectomy, the first postoperative PSA is an independent risk factor for treatment failure. Additional studies are needed to corroborate our observations.

Management of Persistently Elevated Prostate-specific Antigen After Radical Prostatectomy: A Systematic Review of the Literature

CONTEXT

The prognosis and optimal management of pN0/pN1 patients with persistently elevated prostate-specific antigen (PSA) 6-8 wk after radical prostatectomy (RP) remain unclear.

OBJECTIVE

To perform a systematic review of oncologic outcomes and effectiveness of salvage therapies in men with a detectable PSA level after RP.

EVIDENCE ACQUISITION

A systematic review was performed in May 2020. A total of 2374 articles were screened, and 25 studies including 5217 men were selected and included in the systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.

EVIDENCE SYNTHESIS

PSA persistence was most commonly defined as PSA >0.1 ng/ml. PSA persistence was significantly correlated with disease aggressiveness and associated with worse oncologic outcomes than in men with undetectable PSA levels. The 5-yr recurrence-free survival rates varied from 21.5% to 67.0%. The ≥10-yr cancer-specific survival was 75-88%. Salvage radiotherapy ± androgen deprivation therapy was associated with improved survival outcomes. Risk stratification according to pathologic features, PSA levels/kinetics, and genomic classifier may aid in personalization of treatment. The usefulness of molecular imaging in this setting remains underevaluated. Main limitations of this systematic review are the retrospective design of the included studies and the lack of randomized controlled trials (RCTs) focusing on this specific population.

CONCLUSIONS

PSA persistence after RP is strongly correlated with poor oncologic outcomes. Our review suggests a benefit from immediate radiotherapy; however, current evidence is still low. Indication of subsequent therapies should be based on individual discussions, taking into account all the prognostic factors and the efficacy/toxicity imbalance of proposed treatment. Results from ongoing RCTs are awaited to state on the role of more intensified systemic therapy in this population.

PATIENT SUMMARY

Patients with a detectable prostate-specific antigen level after surgery are at high risk of subsequent progression. Immediate radiotherapy might improve survival outcomes. Further research into the role of molecular imaging and genomic classifier is needed in this patient population.

Current and emerging therapies for localized high-risk prostate cancer

Introduction: Despite progress in the field of high-risk localized prostate cancer (HRPCa) treatments, high-risk patients treated with curative intent are at increased risk of biochemical recurrence, metastatic progression and cancer-related death. The optimal treatment strategy remains a topic of debate. This review provides an overview of the current and investigational therapeutic options for HRPCa.Areas covered: A PubMed search was performed for papers on the current perspectives on the multimodality treatment of HRPCa. We focus on both primary local treatment as well as systemic treatment options. Finally, relevant ongoing trials focusing on systemic treatments (including [neo]adjuvant treatments) enrolling at least 50 patients were retrieved, to highlight ongoing research and treatment optimization.Expert opinion: Disease progression in HRPCa patients is driven by local tumor extension and subclinical metastases. Therefore, the main treatment concept is a multimodal approach targeting the primary tumor with extended surgery or RT with long-term ADT and simultaneously targeting micro-metastatic deposits. However, there is still room for optimization. Upcoming clinical trials comparing surgery versus RT as local treatment, trials with (neo)adjuvant chemotherapy or androgen receptor signaling inhibitors will likely change the treatment landscape. However, a multimodal treatment strategy will stay as the cornerstone in the treatment of HRPCa.

The impact of prostate-specific antigen persistence after radical prostatectomy on the efficacy of salvage radiotherapy in patients with primary N0 prostate cancer

OBJECTIVE

To test whether salvage radiotherapy (SRT) in patients with lymph node negative (N0) prostate cancer is equally effective with persistent prostate-specific antigen (PSA) and PSA rising from the undetectable range (<0.1 ng/mL) after radical prostatectomy (RP).

PATIENTS AND METHODS

We assessed post-SRT PSA progression-free survival (PFS) in 555 patients with prostate cancer. The entire cohort was compared with a risk-adjusted subgroup of 112 patient pairs with matching pre-RP PSA level (±10 ng/mL), Gleason score (≤6 vs 7 vs ≥8), and pre-SRT PSA level (±0.5 ng/mL).

RESULTS

The median follow-up was 6.1 years. After RP, PSA was undetectable in 422 and persistent in 133 patients. PSA persistence and a pre-SRT PSA level of ≥0.5 ng/mL reduced Kaplan-Meier rates of PFS significantly. In multivariate analysis of the entire cohort and after risk adjustment, the pre-SRT PSA level but not post-RP PSA persistence was a significant parameter. In the matched cohort's subgroup with early SRT at a PSA level of <0.5 ng/mL, a trend towards a worse outcome with post-RP PSA persistence was observed. Delayed SRT with a PSA level ≥0.5 ng/mL led to a PFS of <30%, irrespective of the post-RP PSA level.

CONCLUSION

In patients with N0 prostate cancer with post-RP PSA persistence, early SRT at a PSA level <0.5 ng/mL seems to be less effective than in recurrent patients with post-RP undetectable PSA. They might benefit from intensified therapy, but larger case numbers are required to substantiate this conclusion. In patients with a PSA level ≥0.5 ng/mL and higher-risk features associated with post-RP PSA persistence, SRT alone is unlikely to provide long-term freedom from further progression.

Performance of a Prostate Cancer Genomic Classifier in Predicting Metastasis in Men with Prostate-specific Antigen Persistence Postprostatectomy

BACKGROUND

Prostate cancer patients who have a detectable prostate-specific antigen (PSA) postprostatectomy may harbor pre-existing metastatic disease. To our knowledge, none of the commercially available genomic biomarkers have been investigated in such men.

OBJECTIVE

To evaluate if a 22-gene genomic classifier can independently predict development of metastasis in men with PSA persistence postoperatively.

DESIGN, SETTING, AND PARTICIPANTS

A multi-institutional study of 477 men who underwent radical prostatectomy (RP) between 1990 and 2015 from three academic centers. Patients were categorized as detectable PSA (n=150) or undetectable (n=327) based on post-RP PSA nadir ≥0.1 ng/ml.

OUTCOME MEASUREMENTS AND STATISITICAL ANALYSIS

Cumulative incidence curves for metastasis were constructed using Fine-Gray competing risks analysis. Penalized Cox univariable and multivariable (MVA) proportional hazards models were performed to evaluate the association of the genomic classifier with metastasis.

RESULTS AND LIMITATIONS

The median follow-up for censored patients was 57 mo. The median time from RP to first postoperative PSA was 1.4 mo. Detectable PSA patients were more likely to have higher adverse pathologic features compared with undetectable PSA patients. On MVA, only genomic high-risk (hazard ratio [HR]: 5.95, 95% confidence interval [CI]: 2.02-19.41, p=0.001), detectable PSA (HR: 4.26, 95% CI: 1.16-21.8, p=0.03), and lymph node invasion (HR: 12.2, 95% CI: 2.46-70.7, p=0.003) remained prognostic factors for metastasis. Among detectable PSA patients, the 5-yr metastasis rate was 0.90% for genomic low/intermediate and 18% for genomic high risk (p<0.001). Genomic high risk remained independently prognostic on MVA (HR: 5.61, 95% CI: 1.48-22.7, p=0.01) among detectable PSA patients. C-index for Cancer of the Prostate Risk Assessment Postsurgical score, Gandaglia nomogram, and the genomic classifier plus either Cancer of the Prostate Risk Assessment Postsurgical score or Gandaglia were 0.69, 0.68, and 0.82 or 0.81, respectively. Sample size was a limitation.

CONCLUSIONS

Despite patients with a detectable PSA harboring significantly higher rates of aggressive clinicopathologic features, Decipher independently predicts for metastasis. Prospective validation of these findings is warranted and will be collected as part of the ongoing randomized trial NRG GU-002.

PATIENT SUMMARY

Decipher independently predicted metastasis for patients with detectable prostate-specific antigen after prostatectomy.

Impact of Early Salvage Radiation Therapy in Patients with Persistently Elevated or Rising Prostate-specific Antigen After Radical Prostatectomy

BACKGROUND

Salvage radiation therapy (SRT) is a recommended treatment option for biochemical recurrence after radical prostatectomy (RP). However, its effectiveness may be limited to specific categories of patients.

OBJECTIVE

We aimed to identify the optimal candidates for early SRT after RP.

DESIGN, SETTING, AND PARTICIPANTS

The study included 925 node-negative patients treated with SRT after RP at seven institutions. Patients received SRT for either prostate-specific antigen (PSA) rising, or PSA persistence after RP that was defined as PSA level ≥0.1 ng/ml at 1 mo after surgery. All patients received local radiation to the prostate and seminal vesicle bed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome measured was distant metastasis after SRT. Regression tree analysis was used to develop a risk-stratification tool. Multivariable Cox regression analysis and nonparametric curve fitting methods were used to explore the relationship between PSA level at SRT and the probability of metastasis-free survival at 8 yr.

RESULTS AND LIMITATIONS

At a median follow-up of 8.0 yr, 130 patients developed distant metastasis. At multivariable analysis, pre-SRT PSA level was significantly associated with distant metastasis (hazard ratio: 1.06, p<0.0001). However, when patients were stratified into five risk groups using regression tree analysis (area under the curve: 85%), early SRT administration provided better metastasis-free survival in three groups only: (1) low risk: undetectable PSA after RP, Gleason score ≤7, and tumour stage ≥pT3b, (2) intermediate risk: undetectable PSA after RP with Gleason score ≥8, (3) high risk: PSA persistence after RP with Gleason score ≤7.

CONCLUSIONS

We developed an accurate risk stratification tool to facilitate the individualised recommendation for early SRT based on prostate cancer characteristics. Early SRT proved to be beneficial only in selected groups of patients who are more likely to be affected by clinically significant but not yet systemic recurrence at the time of salvage treatment administration.

PATIENT SUMMARY

In patients affected by prostate cancer recurrence after radical prostatectomy, the early administration of salvage radiation therapy is beneficial only for selected subgroups of patients. In this study, these groups of patients were identified.