Adjuvant radiation with hormonal therapy is associated with improved survival in men with pathologically involved lymph nodes after radical surgery for prostate cancer

Evaluating the Impact of Prostate Only Versus Pelvic Radiotherapy for Pathological Node-positive Prostate Cancer: First Results from the Multicenter Phase 3 PROPER Trial

BACKGROUND

The optimal treatment for patients with pathological node-positive (pN1) prostate cancer (PCa) is unclear.

OBJECTIVE

To evaluate whether whole-pelvis radiotherapy (WPRT) improves clinical relapse-free survival (cRFS) in comparison to prostate-only radiotherapy (PORT) in pN1 PCa.

DESIGN, SETTING, AND PARTICIPANTS

PROPER was a phase 3 trial randomizing patients to WPRT or PORT. All patients had pN1cM0 PCa with fewer than five lymph nodes involved.

INTERVENTION

All patients underwent pelvic lymph node dissection followed by radical prostatectomy/primary radiotherapy + 2 yr of androgen deprivation therapy (ADT). Patients were randomized to PORT (arm A) or WPRT (arm B).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was cRFS. The secondary endpoints were overall survival (OS), biochemical relapse-free survival (bRFS), and toxicity. The study was stopped because of poor accrual in June 2021 after the inclusion of 69 patients. We report on OS, bRFS, cRFS, and acute and late toxicity.

RESULTS AND LIMITATIONS

The median follow-up was 30 mo in arm A (n = 33) and 36 mo in arm B (n = 31). The 3-yr OS rate was 92% ± 5% in arm A and 93% ± 5% in arm B (p = 0.61). None of the patients died of PCa. The 3-yr bRFS was 79% ± 9% in arm A and 92% ± 5% in arm B (p = 0.08). The 3-yr cRFS rate was 88% ± 6% in arm A and 92% ± 5% in arm B (p = 0.31). No pelvic recurrence was observed in arm B. Acute grade 2 gastrointestinal toxicity was higher with WPRT (15% in arm A vs 45% in arm B; p = 0.03). Limitations are the early closure because of poor accrual and the limited follow-up.

CONCLUSIONS

The results of our trial are hypothesis-generating but add evidence supporting the recommendation to offer WPRT to patients with pN1 PCa. However, WPRT is associated with more acute gastrointestinal toxicity.

PATIENT SUMMARY

We looked at the impact of radiotherapy to the whole pelvis (WPRT) for patients with prostate cancer that had spread to the lymph nodes. Although the trial was closed early because of poor enrolment, we found that WPRT improves survival free from relapse, and no recurrences were observed in the pelvis. WPRT is associated with more acute side effects on the gastrointestinal system in comparison to radiotherapy to just the prostate.

Current Status and Future Perspective on the Management of Lymph Node-Positive Prostate Cancer after Radical Prostatectomy

Pathological lymph node involvement (pN1) after a pelvic lymph node dissection represents one of the most unfavorable prognostic factors for disease recurrence and cancer-specific mortality in prostate cancer. However, optimal management for pN1 patients remains unclear. Thus, the guideline from the European Association of Urology recommends discussing three following management options with pN1 patients after an extended pelvic lymph node dissection, based on nodal involvement characteristics: (i) offer adjuvant androgen-deprivation therapy, (ii) offer adjuvant androgen-deprivation therapy with additional radiotherapy and (iii) offer observation (expectant management) to a patient with ≤2 nodes and a prostate-specific antigen <0.1 ng/mL. Treatment intensification may reduce risks of recurrence and cancer-specific mortality, but it may increase adverse events and impair quality of life. Few randomized control trials for pN1 are under investigation. In addition, there are limited reports on the quality of life and patient-reported outcomes in patients with pN1. Therefore, more research is needed to establish an optimal therapeutic strategy for patients with pN1. This review summarizes current evidence on the treatments available for men with pN1, summarizes randomized control trials that included pN1 prostate cancer, and discusses future perspectives.

Features and management of men with pN1 cM0 prostate cancer after radical prostatectomy and lymphadenectomy: a systematic review of population-based evidence

PURPOSE OF REVIEW

To investigate the features and optimal management of pN+ cM0 prostate cancer (PCa) according to registry-based studies.

RECENT FINDINGS

Up to 15% of PCa patients harbor lymph node invasion (pN+) at radical prostatectomy plus lymph node dissection. Nonetheless, the optimal management strategy in this setting is not well characterized.

SUMMARY

We performed a systematic review including n = 13 studies. Management strategies comprised 13 536 men undergoing observation, 11 149 adjuvant androgen deprivation therapy (aADT), 7,075 adjuvant radiotherapy (aRT) +aADT and 705 aRT. Baseline features showed aggressive PCa in the majority of men. At a median follow-up ranging 48-134months, Cancer-related death was 5% and overall-mortality 16.6%. aADT and aRT alone had no cancer-specific survival or overall survival advantages over observation only and over not performing aRT, respectively. aADT plus aRT yielded a survival benefit compared to observation and aADT, which in one study, were limited to certain intermediate-risk categories. Age, Gleason, Charlson score, positive surgical margins, pathological stage, and positive nodes number, but not prostate specific antigen, were most relevant prognostic factors. Our work further confirmed pN+ PCa is a multifaceted disease and will help future research in defining its optimal management based on different risk categories to maximize survival and patient's quality of life.

On the probability of lymph node negativity in pN0-staged prostate cancer-a theoretically derived rule of thumb for adjuvant needs

Purpose

The extent of lymphadenectomy and clinical features influence the risk of occult nodes in node-negative prostate cancer. We derived a simple estimation model for the negative predictive value (npv) of histopathologically node-negative prostate cancer patients (pN0) to guide adjuvant treatment.

Methods

Approximations of sensitivities in detecting lymph node metastasis from current publications depending on the number of removed lymph nodes were used for a theoretical deduction of a simplified formulation of npv assuming a false node positivity of 0.

Results

A theoretical formula of npv = p(N0IpN0) = (100 − prevalence) / (100 − sensitivity × prevalence) was calculated (sensitivity and preoperative prevalence in %). Depending on the number of removed lymph nodes (nLN), the sensitivity of pN0-staged prostate cancer was derived for three sensitivity levels accordingly: sensitivity = f(nLN) = 9 × nLN /100 for 0 ≤ nLN ≤ 8 and f(nLN) = (nLN + 70) /100 for 9 ≤ nLN ≤ 29 and f(nLN) = 1 for nLN ≥ 30.

Conclusion

We developed a theoretical formula for estimation of the npv in pN0-staged prostate cancer patients. It is a sine qua non to use the formula in a clinically experienced context before deciding to electively irradiate pelvic lymph nodes or to intensify adjuvant systemic treatment.

Narrative review of management strategies and outcomes in node-positive prostate cancer

Pelvic nodal involvement is present in 13% of new prostate cancer diagnoses each year and is associated with a poor prognosis compared to localized disease. Grouped as stage IV along with distant metastatic disease, node-positive nonmetastatic patients historically received systemic therapy alone as primary treatment. This treatment paradigm has shifted as data have demonstrated that these patients may benefit from aggressive locoregional therapy and are potentially curable. There is currently a lack of randomized evidence to define the optimal management for node-positive patients. While a few trials have included node-positive patients, the majority of data are derived from large multi-institutional series or population-based series. This narrative review summarizes the current literature supporting curative-intent management strategies for patients diagnosed with nonmetastatic clinically node-positive prostate cancer (cN1M0), as well as patients found to have pathologic nodal disease at the time of surgery (pN1M0). Treatment of both scenarios requires multimodality considerations including surgery, radiation therapy (RT) and systemic therapy to minimize the risks of both locoregional and distant recurrence. Future considerations include developments in enhanced imaging and systemic therapy. Inclusion of node-positive patients on prospective, randomized trials such as NRG GU 008 is needed to enhance our understanding of optimal management strategies.

Pathologically Node-Positive Prostate Cancer: Casting for Cure When the Die Is Cast?

The postoperative management of men with lymph node involved prostate cancer (pN+) remains a challenge as there is a general lack of randomized trial data and a range of management strategies. Retrospective studies suggest a variable clinic course for patients with pN+ prostate cancer. Some men progress rapidly to metastatic disease despite further therapies, whereas other men can have a period of prolonged quiescence without adjuvant androgen deprivation therapy (ADT) or radiation therapy (RT). For men who have undergone radical prostatectomy, randomized trial data indicate that the addition of ADT in pN+ disease extends metastasis-free, prostate cancer-specific, and overall survival. Additional retrospective studies suggest that adding RT is potentially beneficial in this setting, improving overall and cancer-specific survival especially in men with certain pathologic parameters. Conversely, men with lower disease burden in their lymph nodes have longer times to progression and may be candidates for observation and salvage therapy as opposed to adjuvant ADT/RT.

Adjuvant versus early salvage radiotherapy for prostate cancer patients: Time to move on

In the management of prostate cancer , few treatments have caused as much controversy as adjuvant radiotherapy (ART) after radical prostatectomy in high-risk patients In the present article, we assess the exclusion and inclusion criteria of the 6 randomised trials and 5-year biochemical relapse-free survival and overall survival rates in order to identify the patient subgroups most likely to benefit from ART. We also evaluate treatment-related toxicity and the indications for androgen deprivation therapy . The main aim of this analysis was to determine whether the available evidence, which previously appeared to support ART, now favours early salvage radiotherapy. If so, perhaps we can finally resolve the controversy surrounding the optimal timing of postoperative radiotherapy.

The Horse is at the Stable Door: Management of N1M0 Prostate Cancer

Pelvic lymph node involvement in prostate cancer is a significant poor prognostic factor with very little evidence on the optimal management options for these patients. It is estimated that lymph node-positive patients make up 12% of newly diagnosed prostate cancer and this figure is expected to rise with the advancement and increasing use of novel imaging. The controversy around this subgroup of patients is whether this is an intermediary stage before disseminated disease and hence amenable to curative treatment options. Systemic therapies have been the mainstay of treatment for these patients for decades, but in recent years, studies have emerged supporting the addition of local therapy. This review will focus on the current multimodal management approach for clinical and pathological lymph node-positive prostate cancer with a focus on radiotherapy options and aims to provide the rationale for a curative approach with a combination of local and systemic therapy.

Androgen deprivation therapy in men with node-positive prostate cancer treated with postoperative radiotherapy

BACKGROUND

In men with node-positive prostate cancer after radical prostatectomy there are limited data on the value of adding androgen deprivation therapy (ADT) to postoperative radiotherapy.

OBJECTIVE

To determine whether there is a clear oncologic benefit to ADT in the setting of node-positive prostate cancer treated with postoperative radiotherapy.

METHODS

We analyzed data for 372 prostate cancer patients treated at San Raffaele Hospital with postoperative radiotherapy for node-positive disease after radical prostatectomy, 272 received both ADT and radiotherapy. Eighty-six men were followed without an event for more than 10 years.

RESULTS

Patients who received postoperative radiotherapy + ADT had more aggressive disease, with higher preoperative PSA level, higher rate of ISUP grade 5, pT3b-T4 tumors and ≥3 positive nodes. At multivariable Cox regression, the comparison between men treated by postoperative radiotherapy + ADT vs. radiotherapy alone did not show a significant difference for overall (hazards ratio: 0.91; 95% confidence interval: 0.45, 1.84; P = 0.8) and cancer-specific survival (hazards ratio: 5.39; 95% confidence intervalI: 0.70, 41.39; P = 0.11). These results remained consistent in a number of sensitivity analyses, including propensity score matching. Consideration of 95% CIs suggests that a clinically significant benefit of ADT in node-positive patients receiving radiotherapy after surgery is unlikely.

CONCLUSIONS

We can exclude the sort of large survival benefit that would be required to justify the risks and toxicities of ADT in men with node-positive disease receiving postoperative radiotherapy. Awaiting larger and more powered studies on this topic, men with pN+ prostate cancer treated with postoperative radiotherapy should not receive ADT outside well-controlled clinical trials.

Benefits of Elective Para-Aortic Radiotherapy for pN1 Prostate Cancer Using Arc Therapy (Intensity-Modulated or Volumetric Modulated Arc Therapy): Protocol for a Nonrandomized Phase II Trial

BACKGROUND

In patients with prostate cancer (PCa) with histopathologically proven pelvic lymph node (LN) metastasis (pN1) after extended pelvic lymph node dissection (ePLND), multimodality treatment consisting of treatment of the primary tumor and whole pelvic radiotherapy (WPRT) combined with androgen deprivation therapy (ADT) offers promising results, leading to better cause-specific survival rates compared with ADT alone. However, in case more than one pelvic LN is invaded by the tumor, approximately 40% of the patients relapse biochemically and clinically. Clinical relapse is present in the para-aortic LNs (M1a disease) in up to 77% of the relapsing cases.

OBJECTIVE

We hypothesize that, based on the evidence that positive LNs represent the door to hematogenous dissemination, elective para-aortic irradiation will reduce the development of both retroperitoneal nodal (M1a) and distant metastasis (M1b or M1c disease), postpone the need for palliative ADT, and prolong the time to castration-refractory disease.

METHODS

To test this hypothesis, we will conduct a prospective, nonrandomized phase II trial to study the efficacy of additional elective para-aortic radiotherapy (PART) in pN1 patients compared with those who were historically treated with adjuvant WPRT alone. We aim to include 137 patients with PCa and presence of pN1 disease after ePLND. With this number of patients, an improvement of 15% in the 5-year clinical relapse-free survival can be detected with a power of 80%.

RESULTS

Recruitment of patients for this trial started in 2017 and will be completed approximately by March 2020.

CONCLUSIONS

This is the first phase II trial to investigate the benefits of an elective PART in patients with PCa. The results of this trial will potentially serve as a sound base for a later randomized phase III trial. All participants are given a PART information sheet and required to give written informed consent. Results are expected to be published in a peer-reviewed journal.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03079323; https://clinicaltrials.gov/ct2/show/NCT03079323 (Archived by WebCite at http://www.webcitation.org/73ELimv1d).

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/11256.

Genomic Gain of 16p13.3 in Prostate Cancer Predicts Poor Clinical Outcome after Surgical Intervention

Identifying tumors with high metastatic potential is key to improving the clinical management of prostate cancer. Recently, we characterized a chromosome 16p13.3 gain frequently observed in prostate cancer metastases and now demonstrate the prognostic value of this genomic alteration in surgically treated prostate cancer. Dual-color FISH was used to detect 16p13.3 gain on a human tissue microarray representing 304 primary radical prostatectomy (RP) cases with clinical follow-up data. The results were validated in an external dataset. The 16p13.3 gain was detected in 42% (113/267) of the specimens scorable by FISH and was significantly associated with clinicopathologic features of aggressive prostate cancer, including high preoperative PSA (P = 0.03) levels, high Gleason score (GS, P < 0.0001), advanced pathologic tumor stage (P < 0.0001), and positive surgical margins (P = 0.009). The 16p13.3 gain predicted biochemical recurrence (BCR) in the overall cohort (log-rank P = 0.0005), and in subsets of patients with PSA ≤10 or GS ≤7 (log-rank P = 0.02 and P = 0.006, respectively). Moreover, combining the 16p13.3 gain status with standard prognostic markers improved BCR risk stratification and identified a subgroup of patients with high probability of recurrence. The 16p13.3 gain status was also associated with an increased risk of developing distant metastases (log-rank P = 0.03) further substantiating its role in prostate cancer progression.Implications: This study demonstrates the prognostic significance of the 16p13.3 genomic gain in primary prostate tumors, suggesting potential utility in the clinical management of the disease by identifying patients at high risk of recurrence who may benefit from adjuvant therapies. Mol Cancer Res; 16(1); 115-23. ©2017 AACR.

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.