Upfront Androgen Deprivation Therapy With Salvage Radiation May Improve Biochemical Outcomes in Prostate Cancer Patients With Post-Prostatectomy Rising PSA

Immediate radiotherapy versus observation in patients with node-positive prostate cancer after radical prostatectomy

BACKGROUND

The optimal management of node-positive (pN1) prostate cancer following radical prostatectomy (RP) remains uncertain. Despite randomized evidence, utilization of immediate, life-long androgen deprivation therapy (ADT) remains poor, and recent trials of early salvage radiotherapy included only a minority of pN1 patients. We therefore emulated a hypothetical pragmatic trial of adjuvant radiotherapy versus observation in men with pN1 prostate cancer.

METHODS

Using the RADICALS-RT trial to inform the design of a hypothetical trial, we identified men aged 50-69 years with pT2-3 Rany pN1 M0, pre-treatment PSA < 50 ng/mL prostate cancer in the NCDB from 2006 to 2015 treated with 60-72 Gy of adjuvant RT (aRT) ± ADT within 26 weeks of RP or observation. After estimating a propensity score for receipt of aRT, we estimated absolute and relative treatment effects using stabilized inverse probability of treatment (sIPW) re-weighting.

RESULTS

In total, 3510 patients were included in the study, of whom 587 (17%) received aRT (73% with concurrent ADT). Median follow-up was 40.0 -months, during which 333 deaths occurred. After sIPW re-weighting, baseline characteristics were well-balanced. Adjusted overall survival (OS) was 93% versus 89% at 5-years and 82% versus 79% at 7-years for aRT versus observation (p = 0.11). In IPW-reweighted Cox regression, aRT was associated with a lower risk of all-cause mortality (ACM) than observation, but this did not reach statistical significance (HR 0.70 p = 0.06). In analyses examining heterogeneity of treatment effects, aRT was associated with improved ACM only for men with Gleason 8-10 disease (HR 0.59, p = 0.01), ≥2 positive LNs (HR 0.49, p = 0.04 for 2 positive LNs; HR 0.42, p = 0.01 for ≥3 positive LNs), or negative surgical margins (HR 0.50, p = 0.02).

CONCLUSIONS

In observational analyses designed to emulate a hypothetical target trial of aRT versus observation in pN1 prostate cancer, aRT was associated with improved OS only for men with Gleason 8-10 disease, ≥2 positive LNs, or negative surgical margins.

Effect of Salvage Radiotherapy and Endocrine Therapy on Patients with Biochemical Recurrence After Prostate Cancer Operation- a Meta‑Analysis

CONTEXT

Several studies reported the application of androgen deprivation therapy and radiotherapy in patients with biochemical recurrence after prostate cancer operation.

OBJECTIVE

To perform a systematic review and meta-analysis evaluating of endocrine therapy and radiotherapy in patients with biochemical recurrence after prostate cancer surgery. The primary end point was biochemical progression-free survival (bPFS). Secondary end point was overall survival (OS).

METHODS

A systematic review of PubMed/Medline, Embase, and Cochrane databases to identify relevant studies published in English up to March 2020. Twelve studies were selected for inclusion.

RESULTS

There were 11 studies included in the present study. Including two randomized controlled trials and nine cohort studies. The meta-analysis shows a significant bPFS benefit from androgen deprivation therapy and radiotherapy in patients with biochemical recurrence after prostate cancer operation. (hazard ratio [HR]: 0.57; 95% confidence interval CI, 0.52-0.63; p < .001). For patients with GS < 7 and low-risk patients, combined treatment can have a benefit for BPFs (HR: 0.53; 95% CI, 0.37-0.76; HR: 0.58; 95% CI, 0.36-0.93). Androgen deprivation therapy and radiotherapy in patients with biochemical recurrence was associated with a slightly OS improvement (HR: 0.73; 95% CI, 0.57-0.93; p = 0.01).

CONCLUSIONS

Compared with salvage radiotherapy alone, This meta-analysis shows a significant bPFS benefit from endocrine therapy combined with salvage radiotherapy in patients with biochemical recurrence after prostate cancer operation. And benefit more for high-risk groups. However, there was no significant benefit in group GS ≥ 8. It shows a slightly OS benefit from endocrine therapy combined with salvage radiotherapy in patients with biochemical recurrence.

Contemporary role of postoperative radiotherapy for prostate cancer

While radical prostatectomy (RP) has provided long-term disease control for the majority of patients with localized prostate cancer (CaP), nearly 30% of all surgical patients have disease progression. For high-risk patients, more than half of men experience disease recurrence within 10 years. Postoperative radiotherapy is the only known potentially curative treatment for a large number of patients following prostatectomy. Lately, there have been several advances with the potential to improve outcomes for patients undergoing postoperative radiotherapy. This article will give an overview of the existing literature and current controversies on: (I) timing of postoperative radiation; (II) use of concomitant androgen deprivation therapy; (III) optimal dose to the prostate bed; (IV) use of hypofractionation; (V) elective treatment of the pelvic lymph nodes; (VI) novel imaging modalities, and (VII) genomic biomarkers.

Optimizing the Timing of Salvage Postprostatectomy Radiotherapy and the Use of Concurrent Hormonal Therapy for Prostate Cancer

CONTEXT

Currently, salvage radiotherapy (SRT) is the only known curative intervention for men with recurrent disease following prostatectomy. Critical issues in the optimal selection and management of men being considered for SRT include the threshold prostate-specific antigen (PSA) value at which to initiate treatment (ie, pre-SRT PSA) and the role of concurrent hormonal therapy (HT).

OBJECTIVE

To review the published evidence pertaining to the optimal timing for SRT and the role of concurrent HT.

EVIDENCE ACQUISITION

MEDLINE (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and guideline statements from professional organizations were queried from January 1, 2000 through January 10, 2018.

EVIDENCE SYNTHESIS

Thirty-three independent reports, including two randomized trials evaluating HT with SRT, were identified. Retrospective data suggest that SRT initiation at lower pre-SRT PSA levels is associated with better clinical outcomes. Prospective data suggest an overall survival benefit with concurrent HT that manifests during long-term follow-up, with the caveat that hypothesis-generating subgroup analyses suggest that this benefit may be limited to patients with higher pre-SRT PSA levels. Patients with adverse risk factors, such as Gleason grade group 4-5 disease, are likely to benefit the most from earlier SRT initiation and/or the use of HT.

CONCLUSIONS

Given the limitations of the available data, it is imperative that physicians participate in shared decision-making, with the recommendation tailored for each man's desire to maximize oncologic benefit (with a risk of overtreatment) versus potential quality-of-life optimization (with a risk of undertreatment). Within that framework, a significant body of retrospective data supports initiation of SRT at low pre-SRT PSA values, without an arbitrary absolute threshold. Prospective data suggest a benefit of HT, but this benefit may be greatest in patients with a pre-SRT PSA that is higher than the typical level in most patients receiving "early" SRT. Further research is necessary before absolute recommendations can be made.

PATIENT SUMMARY

Two ways to potentially improve outcomes following salvage radiotherapy for prostate cancer that recurs after prostatectomy are to start treatment at a lower prostate-specific antigen level and to use concurrent hormonal therapy. Our review suggests that the available evidence is imperfect, but highlights that both measures are likely to improve clinical outcomes in general, but perhaps not uniformly and/or consistently for all patients. Physician-patient shared decision-making and further research are critical.

Use of androgen deprivation and salvage radiation therapy for patients with prostate cancer and biochemical recurrence after prostatectomy

AIM

Overview on the use of androgen deprivation therapy (ADT) added to salvage radiation therapy (SRT) for prostate cancer patients with biochemical recurrence after prostatectomy.

METHODS

The German Society of Radiation Oncology (DEGRO) expert panel summarized available evidence published between January 2009 and May 2017, and assessed the validity of the information on outcome parameters including overall survival (OS) and treatment-related toxicity.

RESULTS

Two randomized controlled trials and nine relevant retrospective analyses were identified. The RTOG 9601 trial showed an OS improvement for the combination of 2 years of bicalutamide and SRT compared to SRT alone after a median follow-up of 13 years. This improvement appeared to be restricted to those patients with a prostate specific antigen (PSA) level before SRT of ≥0.7 ng/mL. The GETUG AFU-16 trial showed that after a median follow-up of 5 years, the addition of 6 months of goserelin to SRT improved progression-free survival (PFS; based on biochemical recurrence) as compared to SRT alone. ADT in both trials was not associated with increased major late toxicities. Results of retrospective series were inconsistent with a suggestion that the addition of ADT improved biochemical PFS especially in patients with high-risk factors such as Gleason Score ≥8 and in the group with initially negative surgical margins.

CONCLUSIONS

ADT combined with SRT appears to improve OS in patients with a PSA level before SRT of ≥0.7 ng/mL. In patients without persistent PSA after prostatectomy and PSA levels of <0.7 ng/mL, ADT should not routinely be used, but may be considered in patients with additional risk factors such as Gleason Score ≥8 and negative surgical margins.

Long-term Outcome of Prostate Cancer Patients Who Exhibit Biochemical Failure Despite Salvage Radiation Therapy After Radical Prostatectomy

OBJECTIVES

Salvage radiation therapy (SRT) is an effective treatment for recurrent prostate cancer (PCa) after radical prostatectomy. We report the long-term outcome of men who developed biochemical recurrence (BCR) after SRT and were treated >14 years ago.

METHODS

In total, 61 patients treated with SRT from 1992 to 2000 at our institution were identified. Survival was calculated by Kaplan-Meier method. Log-rank test and Cox regression were used to determine significance of clinical parameters.

RESULTS

The median follow-up was 126 months (interquartile range, 66-167 mo). Thirty-four (56%) had prostate-specific antigen (PSA) failure after SRT. At 10 years, overall survival (OS) was 67%, freedom from PSA failure (FFPF) was 33%, prostate cancer-specific survival (PCSS) was 84%, and distant metastases-free survival (DMFS) was 84%. Pathologic T-stage, Gleason score, seminal vesicle involvement, and pre-SRT PSA were associated with FFPF. For patients who failed SRT, the median time to BCR after SRT was 30 mo. A total of 19 (68%) received androgen deprivation therapy. The median OS was 13.6 years. At 10 years from time of BCR, OS was 59%, PCSS was 73%, DMFS was 75%, and castration-resistant-free survival was 70%. Early SRT failure correlated with significantly decreased DMFS and PCSS. Ten-year DMFS from SRT was 43% (BCR≤1 y) versus 91% (BCR>1 y).

CONCLUSIONS

Extended follow-up demonstrates that despite SRT failure, PCSS remains high in select patients. Early failure (≤1 y after SRT) predicted for significantly worse outcome and may represent a subgroup with more aggressive disease that may be considered for further prospective clinical studies.

Adjuvant and Salvage Radiotherapy after Radical Prostatectomy in Prostate Cancer Patients

CONTEXT

Prostate cancer (PCa) patients found to have adverse pathologic features following radical prostatectomy (RP) are less likely to be cured with surgery alone.

OBJECTIVE

To analyze the role of postoperative radiotherapy (RT) in patients with aggressive PCa.

EVIDENCE ACQUISITION

We performed a systematic literature review of the Medline and EMBASE databases. The search strategy included the terms radical prostatectomy, adjuvant radiotherapy, and salvage radiotherapy, alone or in combination. We limited our search to studies published between January 2009 and August 2016.

EVIDENCE SYNTHESIS

Three randomized trials demonstrated that immediate RT after RP reduces the risk of recurrence in patients with aggressive PCa. However, immediate postoperative RT is associated with an increased risk of acute and late side effects ranging from 15% to 35% and 2% to 8%, respectively. Retrospective studies support the oncologic efficacy of initial observation followed by salvage RT administered at the first sign of recurrence; however, the impact of this delay on long-term control remains uncertain. Hopefully, ongoing randomized trials will shed light on the role of adjuvant RT versus observation±salvage RT in individuals with adverse features at RP. Accurate patient selection based on clinical characteristics and molecular profile is crucial. Dose escalation, whole-pelvis RT, novel techniques, and the use of hormonal therapy might improve the outcomes of postoperative RT.

CONCLUSIONS

Immediate RT reduces the risk of recurrence after RP in patients with aggressive disease. However, this approach is associated with an increase in the incidence of short- and long-term side effects. Observation followed by salvage RT administered at the first sign of recurrence might be associated with durable cancer control, but prospective randomized comparison with adjuvant RT is still awaited. Dose escalation, refinements in the technique, and the concomitant use of hormonal therapies might improve outcomes of patients undergoing postoperative RT.

PATIENT SUMMARY

Postoperative radiotherapy has an impact on oncologic outcomes in patients with aggressive disease characteristics. Salvage radiotherapy administered at the first sign of recurrence might be associated with durable cancer control in selected patients but might compromise cure in others.

Salvage radiotherapy with or without short-term hormone therapy for rising prostate-specific antigen concentration after radical prostatectomy (GETUG-AFU 16): a randomised, multicentre, open-label phase 3 trial

BACKGROUND

How best to treat rising prostate-specific antigen (PSA) concentration after radical prostatectomy is an urgent clinical question. Salvage radiotherapy delays the need for more aggressive treatment such as long-term androgen suppression, but fewer than half of patients benefit from it. We aimed to establish the effect of adding short-term androgen suppression at the time of salvage radiotherapy on biochemical outcome and overall survival in men with rising PSA following radical prostatectomy.

METHODS

This open-label, multicentre, phase 3, randomised controlled trial, was done in 43 French study centres. We enrolled men (aged ≥18 years) who had received previous treatment for a histologically confirmed adenocarcinoma of the prostate (but no previous androgen deprivation therapy or pelvic radiotherapy), and who had stage pT2, pT3, or pT4a (bladder neck involvement only) in patients who had rising PSA of 0·2 to less than 2·0 μg/L following radical prostatectomy, without evidence of clinical disease. Patients were randomly assigned (1:1) centrally via an interactive web response system to standard salvage radiotherapy (three-dimensional [3D] conformal radiotherapy or intensity modulated radiotherapy, of 66 Gy in 33 fractions 5 days a week for 7 weeks) or radiotherapy plus short-term androgen suppression using 10·8 mg goserelin by subcutaneous injection on the first day of irradiation and 3 months later. Randomisation was stratified using a permuted block method according to investigational site, radiotherapy modality, and prognosis. The primary endpoint was progression-free survival, analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00423475.

FINDINGS

Between Oct 19, 2006, and March 30, 2010, 743 patients were randomly assigned, 374 to radiotherapy alone and 369 to radiotherapy plus goserelin. Patients assigned to radiotherapy plus goserelin were significantly more likely than patients in the radiotherapy alone group to be free of biochemical progression or clinical progression at 5 years (80% [95% CI 75-84] vs 62% [57-67]; hazard ratio [HR] 0·50, 95% CI 0·38-0·66; p<0·0001). No additional late adverse events occurred in patients receiving short-term androgen suppression compared with those who received radiotherapy alone. The most frequently occuring acute adverse events related to goserelin were hot flushes, sweating, or both (30 [8%] of 366 patients had a grade 2 or worse event; 30 patients [8%] had hot flushes and five patients [1%] had sweating in the radiotherapy plus goserelin group vs none of 372 patients in the radiotherapy alone group). Three (8%) of 366 patients had grade 3 or worse hot flushes and one patient had grade 3 or worse sweating in the radiotherapy plus goserelin group versus none of 372 patients in the radiotherapy alone group. The most common late adverse events of grade 3 or worse were genitourinary events (29 [8%] in the radiotherapy alone group vs 26 [7%] in the radiotherapy plus goserelin group) and sexual disorders (20 [5%] vs 30 [8%]). No treatment-related deaths occurred.

INTERPRETATION

Adding short-term androgen suppression to salvage radiotherapy benefits men who have had radical prostatectomy and whose PSA rises after a postsurgical period when it is undetectable. Radiotherapy combined with short-term androgen suppression could be considered as a reasonable option in this population.

FUNDING

French Ministry of Health, AstraZeneca, and La Ligue Contre le Cancer.

Significance of early prostate-specific antigen values after salvage radiotherapy in recurrent prostate cancer patients treated with surgery

OBJECTIVES

To assess the use of post-salvage radiotherapy prostate-specific antigen for early prediction of biochemical failure or clinical recurrence after salvage radiotherapy in recurrent prostate cancer patients after prostatectomy.

METHODS

From 2000 to 2011, 164 patients were treated with salvage radiotherapy alone for recurrent prostate cancer. Patients who received androgen deprivation therapy before or within 1 month of the termination of salvage radiotherapy were excluded. Survival analysis was carried out with: (i) a selected prostate-specific antigen reference value (0.2 ng/mL) at the second follow-up period (4 months) after salvage radiotherapy (prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months); and (ii) prostate-specific antigen percent decline (post-salvage radiotherapy 4 months prostate-specific antigen/pre-salvage radiotherapy prostate-specific antigen).

RESULTS

The median follow-up time was 53.4 months (range 8.5-134.1 months). The 5-year clinical recurrence-free survival was 87.9%. Prostate-specific antigen percent decline of 0.45 was set as the cut-off value for clinical recurrence-free survival based on the receiver operating characteristics curve. In the multivariate analysis, a prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months (P = 0.013) and prostate-specific antigen percent decline ≥ 0.45 (P = 0.002) were both significant parameters predicting clinical recurrence-free survival. Otherwise, prostate-specific antigen percent decline ≥ 0.45 was the only statistically significant predictor of biochemical failure-free survival (biochemical failure-free survival after salvage radiotherapy).

CONCLUSIONS

A prostate-specific antigen value over 0.2 ng/mL at post-salvage radiotherapy 4 months and prostate-specific antigen percent decline ≥ 0.45 are negative predictors of clinical recurrence-free survival after salvage radiotherapy. Prostate-specific antigen percent decline ≥ 0.45 is also associated with worse biochemical failure-free survival after salvage radiotherapy. Patients with delayed prostate-specific antigen decrease should be carefully observed for clinical recurrence.