Contemporary Patterns of Care and Outcomes of Men Found to Have Lymph Node Metastases at the Time of Radical Prostatectomy

Variation in management of lymph node positive prostate cancer after radical prostatectomy within a statewide quality improvement consortium

BACKGROUND

Patients with lymph node positive (pN+) disease found at the time of radical prostatectomy with pelvic lymphadenectomy for clinically localized prostate cancer (CaP) are at high risk of disease persistence and progression. Contemporary management trends of pN+ CaP are not well described.

MATERIALS AND METHODS

Patients in the Michigan Urologic Surgery Improvement Collaborative (MUSIC) with clinically localized prostate cancer who underwent radical prostatectomy between 2012 and 2023 with cN0/pN+ disease were identified. The primary outcome was to evaluate patient and practice-level factors associated with time to secondary post-RP treatment. Secondary outcomes included practice-level variation in management of pN+ CaP and rates of secondary treatment modality. To assess factors associated with secondary treatment, a Cox proportional hazards model of a 60-day landmark analysis was performed.

RESULTS

We identified 666 patients with pN+ disease. Overall, 66% underwent secondary treatment within 12 months post-RP. About 19% of patients with detectable post-RP PSA did not receive treatment. Of patients receiving secondary treatment after 60-days post-RP, 34% received androgen deprivation therapy (ADT) alone, 27% received radiation (RT) alone, 36% received combination, and 4% received other systemic therapies. In the multivariable model, pathologic grade group (GG)3 (HR 1.5; 95%CI: 1.05-2.14), GG4-5 (HR 1.65; 95%CI: 1.16-2.34), positive margins (HR 1.46; 95%CI: 1.13-1.88), and detectable postoperative PSA ≥0.1 ng/ml (HR 3.46; 95%CI: 2.61-4.59) were significantly associated with secondary post-RP treatment. There was wide variation in adjusted practice-level 12-month secondary treatment utilization (28%-79%).

CONCLUSIONS

The majority pN+ patients receive treatment within 12 months post-RP which was associated with high-risk pathological features and post-RP PSA. Variation in management of pN+ disease highlights the uncertainty regarding the optimal management. Understanding which patients will benefit from secondary treatment, and which type, will be critical to minimize variation in care.

Identifying low cancer-specific mortality risk lymph node-positive radical prostatectomy patients

OBJECTIVES

To identify low cancer-specific mortality (CSM) risk lymph node-positive (pN1) radical prostatectomy (RP) patients.

METHODS

Within Surveillance, Epidemiology and End Results database (2010-2015) pN1 RP patients were identified. Kaplan-Meier plots and multivariable Cox-regression (MCR) models were used. Pathological characteristics were used to identify patients at lowest CSM risk.

RESULTS

Overall, 2197 pN1 RP patients were identified. Overall, 5-year cancer-specific survival (CSS) rate was 93.3%. In MCR models ISUP GG1-2 (hazard ratio [HR]: 0.12, p < 0.001), GG3 (HR: 0.14, p < 0.001), GG4 (HR: 0.35, p = 0.002), pT2 (HR: 0.27, p = 0.012), pT3a (HR: 0.28, p = 0.003), pT3b (HR: 0.39, p = 0.009), and 1-2 positive lymph nodes (HR: 0.64, p = 0.04) independently predicted lower CSM. Pathological characteristics subgroups with the most protective hazard ratios were used to identify low-risk (ISUP GG1-3 and pT2-3a and 1-2 positive lymph nodes) patients versus others (ISUP GG4-5 or pT3b-4 or ≥3 positive lymph nodes). In Kaplan-Meier analyses, 5-year CSS rates were 99.3% for low-risk (n = 480, 21.8%) versus 91.8% (p < 0.001) for others (n = 1717, 78.2%).

CONCLUSIONS

Lymph node-positive RP patients exhibit variable CSS rates. Within this heterogeneous group, those at very low risk of CSM may be identified based on pathological characteristics, namely ISUP GG1-3, pT2-3a, and 1-2 positive lymph nodes. Such stratification scheme might be of value for individual patients counseling, as well as in design of clinical trials.

Transperineal template saturation and conventional biopsy for stage prediction in prostate cancer

OBJECTIVE

To evaluate the performance of risk calculators (RCs) predicting lymph node invasion (LNI) and extraprostatic extension (EPE) in men undergoing transperineal magnetic resonance imaging/transrectal ultrasound (TRUS)-fusion template saturation biopsy (TTSB) and conventional systematic TRUS-guided biopsy (SB).

PATIENTS AND METHODS

The RCs were tested in a consecutive cohort of 645 men undergoing radical prostatectomy with extended pelvic LN dissection between 2005 and 2019. TTSB was performed in 230 (35.7%) and SB in 415 (64.3%) men. Risk of LNI and EPE was calculated using the available RCs. Discrimination, calibration, and clinical usefulness stratified by different biopsy techniques were assessed.

RESULTS

Lymph node invasion was observed in 23 (10%) and EPE in 73 (31.8%) of cases with TTSB and 53 (12.8%) and 158 (38%) with SB, respectively. RCs showed an excellent discrimination and acceptable calibration for prediction of LNI based on TTSB (area under the curve [AUC]/risk estimation: Memorial Sloan Kettering Cancer Center [MSKCC]-RC 0.79/-4%, Briganti (2012)-RC 0.82/-4%, Gandaglia-RC 0.81/+6%). These were comparable in SB (MSKCC-RC 0.78/+2%; Briganti (2012)-RC 0.77/-3%). Decision curve analysis (DCA) revealed a net benefit at threshold probabilities between 3% and 6% when TTSB was used. For prediction of EPE based on TTSB an inferior discrimination and variable calibration were observed (AUC/risk estimation: MSKCC-RC 0.71/+8% and Martini (2018)-RC 0.69/+2%) achieving a net benefit on DCA only at risk thresholds of >17%. Performance of RCs for prediction of LNI and EPE based on SB showed comparable results with a better performance in the DCA for LNI (risk thresholds 1-2%) and poorer performance for EPE (risk threshold >20%). This study is limited by its retrospective single-institution design.

CONCLUSIONS

The potentially more accurate grading ability of TTSB did not result in improved performance of preoperative RCs. Prediction tools for LNI proved clinical usefulness while RCs for EPE did not.

Development of machine learning prognostic models for overall survival of prostate cancer patients with lymph node-positive

Prostate cancer (PCa) patients with lymph node involvement (LNI) constitute a single-risk group with varied prognoses. Existing studies on this group have focused solely on those who underwent prostatectomy (RP), using statistical models to predict prognosis. This study aimed to develop an easily accessible individual survival prediction tool based on multiple machine learning (ML) algorithms to predict survival probability for PCa patients with LNI. A total of 3280 PCa patients with LNI were identified from the Surveillance, Epidemiology, and End Results (SEER) database, covering the years 2000-2019. The primary endpoint was overall survival (OS). Gradient Boosting Survival Analysis (GBSA), Random Survival Forest (RSF), and Extra Survival Trees (EST) were used to develop prognosis models, which were compared to Cox regression. Discrimination was evaluated using the time-dependent areas under the receiver operating characteristic curve (time-dependent AUC) and the concordance index (c-index). Calibration was assessed using the time-dependent Brier score (time-dependent BS) and the integrated Brier score (IBS). Moreover, the beeswarm summary plot in SHAP (SHapley Additive exPlanations) was used to display the contribution of variables to the results. The 3280 patients were randomly split into a training cohort (n = 2624) and a validation cohort (n = 656). Nine variables including age at diagnosis, race, marital status, clinical T stage, prostate-specific antigen (PSA) level at diagnosis, Gleason Score (GS), number of positive lymph nodes, radical prostatectomy (RP), and radiotherapy (RT) were used to develop models. The mean time-dependent AUC for GBSA, RSF, and EST was 0.782 (95% confidence interval [CI] 0.779-0.783), 0.779 (95% CI 0.776-0.780), and 0.781 (95% CI 0.778-0.782), respectively, which were higher than the Cox regression model of 0.770 (95% CI 0.769-0.773). Additionally, all models demonstrated almost similar calibration, with low IBS. A web-based prediction tool was developed using the best-performing GBSA, which is accessible at https://pengzihexjtu-pca-n1.streamlit.app/ . ML algorithms showed better performance compared with Cox regression and we developed a web-based tool, which may help to guide patient treatment and follow-up.

Oncologic outcomes of patients with lymph node invasion at prostatectomy and post-prostatectomy biochemical persistence

BACKGROUND

Pathologic nodal invasion at prostatectomy is frequently associated with persistently elevated prostate-specific antigen (PSA) and with increased risk of disease recurrence. Management strategies for these patients are poorly defined. We aimed to explore the long-term oncologic outcomes and patterns of disease progression.

METHODS

We included men treated between 2000 and 2017 who had lymph node invasion at radical prostatectomy and persistently detectable prostate-specific antigen post-prostatectomy. Postoperative imaging and management strategies were collated. Patterns of recurrence and probability of metastasis-free survival, prostate cancer-specific survival, and overall survival (OS) were assessed.

RESULTS

Among our cohort of 253 patients, 126 developed metastasis. Twenty-five had a positive scan within 6 months of surgery; of these, 15 (60%) had a nodal metastasis, 10 (40%) had a bone metastasis, and 4 (16%) had local recurrence. For metastasis-free survival, 5- and 10-year probabilities were 52% (95% CI 45%, 58%) and 37% (95% CI 28%, 46%), respectively. For prostate cancer-specific survival, 5- and 10-year probabilities were 89% (95% CI 84%, 93%) and 67% (95% CI 57%, 76%), respectively. A total of 221 patients proceeded to hormonal deprivation treatment alone. Ten patients received postoperative radiotherapy.

CONCLUSIONS

Biochemical persistence in patients with lymph node invasion is associated with high risk of disease progression and reduced prostate cancer-specific survival. Management was hindered by the limitation of imaging modalities utilized during the study period in accurately detecting residual disease. Novel molecular imaging may improve staging and help design a therapeutic strategy adapted to patients' specific needs.

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.

Prevalence of High-Risk Prostate Cancer Metastasis to Cloquet's Ilioinguinal Lymph Node

PURPOSE

Cloquet's node, located at the junction between the deep inguinal nodes and the external iliac chain, is easily accessible and commonly excised during pelvic lymph node dissection for prostate cancer. However, we hypothesize that Cloquet's node is not part of lymphatic metastatic spread of prostate cancer.

MATERIALS AND METHODS

Between September 2016 and June 2019, 105 consecutive patients with high-risk prostate cancer (cT3a or Grade Group 4/5, or prostate specific antigen >20 ng/ml) underwent a laparoscopic radical prostatectomy and pelvic lymph node dissection. First, Cloquet's node was identified, retrieved and submitted separately to pathology as right and left Cloquet's node. Next, a pelvic lymph node dissection was completed including the external iliac, obturator fossa and hypogastric nodal packets. Each lymph node was cut into 3 mm slices which were separately embedded in paraffin, stained with hematoxylin and eosin, and examined microscopically.

RESULTS

The final analysis included 95 patients. In this high-risk population, the median number of nodes removed was 22 (IQR 18-29); 39/95 patients (41%) had lymph node metastasis. The median number of Cloquet's nodes removed was 2 (IQR 2-3). Cloquet's node was negative in all but 1 patient (1.1%), who had very high-risk features and high metastatic burden in the lymph nodes.

CONCLUSIONS

In high-risk prostate cancer, metastasis to the ilioinguinal node of Cloquet is rare. Given this low prevalence, Cloquet's node can be safely excluded from the pelvic lymph node dissection template.

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.

Patients with Positive Lymph Nodes after Radical Prostatectomy and Pelvic Lymphadenectomy-Do We Know the Proper Way of Management?

Lymph node invasion in prostate cancer is a significant prognostic factor indicating worse prognosis. While it significantly affects both survival rates and recurrence, proper management remains a controversial and unsolved issue. The thorough evaluation of risk factors associated with nodal involvement, such as lymph node density or extracapsular extension, is crucial to establish the potential expansion of the disease and to substratify patients clinically. There are multiple strategies that may be employed for patients with positive lymph nodes. Nowadays, therapeutic methods are generally based on observation, radiotherapy, and androgen deprivation therapy. However, the current guidelines are incoherent in terms of the most effective management approach. Future management strategies are expected to make use of novel diagnostic tools and therapies, such as photodynamic therapy or diagnostic imaging with prostate-specific membrane antigen. Nevertheless, this heterogeneous group of men remains a great therapeutic concern, and both the clarification of the guidelines and the optimal substratification of patients are required.

Radiotherapy plus androgen-deprivation therapy for PSA persistence in lymph node-positive prostate cancer

The treatment for lymph node involvement (LNI) after radical prostatectomy (RP) has not been established. This study aimed to reveal the outcomes of various management strategies among patients with LNI after RP. Retrospectively, 561 patients with LNI after pelvic lymph node dissection (PLND) with RP treated between 2006 and 2019 at 33 institutions participating in the Japanese Urological Oncology Group were investigated. Metastasis-free survival (MFS) was the primary outcome. Patients were stratified by PSA persistence after RP. Cox regression models were used to analyze the relationships between clinicopathological characteristics and survival. Survival analyses were conducted using the Kaplan-Meier method and log-rank test with or without propensity score matching. Prognoses, including MFS and overall survival, were prominently inferior among patients with persistent PSA than among those without persistent PSA. In multivariate analysis, androgen-deprivation therapy (ADT) plus radiotherapy (RT) was associated with better MFS than ADT alone among patients with persistent PSA (hazard ratio = 0.37; 95% confidence interval = 0.15-0.93; P = 0.034). Similarly, MFS and overall survival were significantly better for ADT plus RT than for ADT alone among patients with persistent PSA after propensity score matching. This study indicated that PSA persistence in LNI prostate cancer increased the risk of poor prognoses, and intensive treatment featuring the addition of RT to ADT might improve survival.

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.

Management of Patients with Node-positive Prostate Cancer at Radical Prostatectomy and Pelvic Lymph Node Dissection: A Systematic Review

CONTEXT

Optimal management of prostate cancer (PCa) patients with lymph node invasion at radical prostatectomy and pelvic lymph node dissection still remains unclear.

OBJECTIVE

To assess the effectiveness of postoperative treatment strategies for pathologically node-positive PCa patients. The secondary aim was to identify the most relevant prognostic factors to guide the management of pN1 patients.

EVIDENCE ACQUISITION

A systematic review was performed in January 2020 using Medline, Embase, and other databases. A total of 5063 articles were screened, and 26 studies including 12 537 men were selected for data synthesis and included in the current review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations.

EVIDENCE SYNTHESIS

Ten-year biochemical recurrence (BCR)-free, clinical recurrence-free, cancer-specific (CSS), and overall (OS) survival rates ranged from 28% to 56%, 70% to 92%, 72% to 98%, and 60% to 87.6%, respectively. A total of seven, five, and six studies assessed the oncological outcomes of observation, adjuvant radiotherapy (aRT), or adjuvant androgen deprivation therapy (ADT), respectively. Initial observation followed by salvage therapies at the time of recurrence represents a safe option in selected patients with a low disease burden. The use of aRT with or without ADT might improve survival in men with locally advanced disease and a higher number of positive nodes. Risk stratification according to pathological Gleason score, number of positive nodes, pathological stage, and surgical margins status is the key to risk stratification and selection of the optimal postoperative therapy. Limitations of this systematic review are the retrospective design of the studies included and the lack of data on adverse events.

CONCLUSIONS

While the majority of men with pN1 disease would experience BCR after surgery, long-term disease-free survival has been reported in selected patients. Management options to improve oncological outcomes include observation versus adjuvant therapies such as aRT and/or ADT. Disease characteristics should be used to select the optimal postoperative management for pN1 PCa patients.

PATIENT SUMMARY

Finding node-positive prostate cancer after a radical prostatectomy often leads to high postoperative prostate-specific antigen levels and is overall a poor prognostic factor. However, this does not necessarily translate into poor survival for all men. Management can be tailored to the severity of disease and options include observation, androgen deprivation therapy, and/or radiotherapy.

[Trivialization of prostate cancer? : Stage shift and possible causes]

BACKGROUND

According to the strongly negative grade D recommendation of the U.S. Preventive Services Task Force in 2012, the prostate-specific antigen (PSA) test was not only not recommended but was also warned against. As a result in the USA there was a stage shift towards more advanced tumor stages under the newly detected prostate cancers; however, in contrast to the highly questionable American PLCO study, the European ERSPC study showed a clear reduction in prostate cancer-related mortality.

OBJECTIVE

In this patient cohort it was investigated whether the tumor stage distribution in curatively treated prostate cancer has significantly changed, whether this has an influence on the perioperative results and complication rates and how these changes could have occurred.

MATERIAL AND METHODS

Patients after radical prostatectomy from 2008 to 2010 were compared to those from 2017. Demographic data, intraoperative courses, perioperative and postoperative complications and histopathological results were compared.

RESULTS

A total of 1276 operations were analyzed. Preoperative PSA levels showed a significant increase in 2017 (10.5 ± 13.4 ng/ml vs. 8.4 ± 9.1 ng/ml, p = 0.032). The pathological staging revealed a 20% increase in T3 tumors (49.4% versus 29.0%, p < 0.001). Correspondingly, moderately and poorly differentiated cancers and therefore those with higher aggressiveness were significantly more frequent with 11.2% (p < 0.001) and 10.4% (p < 0.001), respectively. The number of patients with lymph node metastases at prostatectomy even increased fourfold (4.5% vs. 16.9%, p < 0.001).

CONCLUSION

In the radical prostatectomy group, there was a shift to unfavorable and metastatic tumor stages. This negative trend seems largely to be caused by a lower acceptance of early detection by means of PSA determination.

Current controversies on the role of lymphadenectomy for prostate cancer

Lymph node dissection is part of the standard treatment protocol for various cancers, but its role in prostate cancer has been debatable for some time. Pelvic lymphadenectomy has been shown to better help stage prostate cancer patients, but has yet to be definitively proven to be of any benefit for survival. Various templates for lymph node dissections exist, and though some national guidelines have endorsed an extended pelvic node dissection, the choice of template is still controversial. Pelvic lymphadenectomy may lead to a slightly higher rate complications and operative time, and their use must be judiciously applied to patients with a high enough risk of lymph node involvement. We present a comprehensive review of the literature regarding the benefits and harms of lymph node dissection in prostate cancer.