Pelvic lymph node dissection and its extent on survival benefit in prostate cancer patients with a risk of lymph node invasion >5%: a propensity score matching analysis from SEER database

Management of Patients with Advanced Prostate Cancer. Report from the 2024 Advanced Prostate Cancer Consensus Conference (APCCC)

BACKGROUND AND OBJECTIVE

Innovations have improved outcomes in advanced prostate cancer (PC). Nonetheless, we continue to lack high-level evidence on a variety of topics that greatly impact daily practice. The 2024 Advanced Prostate Cancer Consensus Conference (APCCC) surveyed experts on key questions in clinical management in order to supplement evidence-based guidelines. Here we present voting results for questions from APCCC 2024.

METHODS

Before the conference, a panel of 120 international PC experts used a modified Delphi process to develop 183 multiple-choice consensus questions on eight different topics. Before the conference, these questions were administered via a web-based survey to the voting panel members ("panellists").

KEY FINDINGS AND LIMITATIONS

Consensus was a priori defined as ≥75% agreement, with strong consensus defined as ≥90% agreement. The voting results show varying degrees of consensus, as discussed in this article and detailed in the Supplementary material. These findings do not include a formal literature review or meta-analysis.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The voting results can help physicians and patients navigate controversial areas of clinical management for which high-level evidence is scant or conflicting. The findings can also help funders and policymakers in prioritising areas for future research. Diagnostic and treatment decisions should always be individualised on the basis of patient and cancer characteristics, and should incorporate current and emerging clinical evidence, guidelines, and logistic and economic factors. Enrolment in clinical trials is always strongly encouraged. Importantly, APCCC 2024 once again identified important gaps (areas of nonconsensus) that merit evaluation in specifically designed trials.

From foes to friends: rethinking the role of lymph nodes in prostate cancer

Clinically localized prostate cancer is often treated with radical prostatectomy combined with pelvic lymph node dissection. Data suggest that lymph node dissection does improve disease staging, but its therapeutic value has often been debated, with few studies showing that lymph node removal directly improves oncological outcomes; however, lymph nodes are an important first site of antigen recognition and immune system activation and the success of many currently used immunological therapies hinges on this dogma. Evidence, particularly in the preclinical setting, has demonstrated that the success of immune checkpoint inhibitors is dampened by the removal of tumour-draining lymph nodes. Thus, whether lymph nodes are truly 'foes' or whether they are actually 'friends' in oncological care is an important idea to discuss.

A comparative analysis of perioperative complications and biochemical recurrence between standard and extended pelvic lymph node dissection in prostate cancer patients undergoing radical prostatectomy: a systematic review and meta-analysis

INTRODUCTION

Pelvic lymph node dissection (PLND) is commonly performed during radical prostatectomy (RP) for prostate cancer staging. This study aimed to comprehensively analyze existing evidence compare perioperative complications associated with standard (sPLND) versus extended PLND templates (ePLND) in RP patients.

METHODS

A meta-analysis of prospective studies on PLND complications was conducted. Systematic searches were performed on Web of Science, Pubmed, Embase, and the Cochrane Library until May 2023. Risk ratios (RRs) were estimated using random-effects models in the meta-analysis. The statistical analysis of the data was carried out using Review Manager software.

RESULTS

Nine studies, including three randomized clinical trial and six prospective studies, with a total of 4962 patients were analyzed. The meta-analysis revealed that patients undergoing ePLND had a higher risk of partial perioperative complications, such as lymphedema ( I2 =28%; RR 0.05; 95% CI: 0.01-0.27; P <0.001) and urinary retention ( I2 =0%; RR 0.30; 95% CI: 0.09-0.94; P =0.04) compared to those undergoing sPLND. However, there were no significant difference was observed in pelvic hematoma ( I2 =0%; RR 1.65; 95% CI: 0.44-6.17; P =0.46), thromboembolic ( I2 =57%; RR 0.91; 95% CI: 0.35-2.38; P =0.85), ureteral injury ( I2 =33%; RR 0.28; 95% CI: 0.05-1.52; P =0.14), intraoperative bowel injury ( I2 =0%; RR 0.87; 95% CI: 0.14-5.27; P =0.88), and lymphocele ( I2 =0%; RR 1.58; 95% CI: 0.54-4.60; P =0.40) between sPLND and ePLND. Additionally, no significant difference was observed in overall perioperative complications ( I2 =85%; RR 0.68; 95% CI: 0.40-1.16; P =0.16). Furthermore, ePLND did not significantly reduce biochemical recurrence ( I2 =68%; RR 0.59; 95% CI: 0.28-1.24; P =0.16) of prostate cancer.

CONCLUSION

This analysis found no significant differences in overall perioperative complications or biochemical recurrence between sPLND and ePLND, but ePLND may offer enhanced diagnostic advantages by increasing the detection rate of lymph node metastasis.

The relationship between biochemical recurrence and number of lymph nodes removed during surgery for localized prostate cancer

PURPOSE

To assess whether completeness of pelvic lymph node dissection (PLND) as measured by lymph node yield reduces biochemical recurrence (BCR) in men undergoing radical prostatectomy (RP) for prostate cancer (PCa), stratified according to Briganti nomogram-derived risk (≥5% vs. < 5%) of lymph node invasion (LNI).

METHODS

Retrospective study of 3724 men who underwent RP between January 1995 and January 2015 from our prospectively collected institutional database. All men included had minimum five years follow-up and were not given androgen deprivation therapy or radiotherapy prior to BCR. Primary endpoint was time to BCR as defined by PSA > 0.2ng/ml. Patients were analysed according to Briganti Nomogram derived risk of 'low-risk' (< 5%) vs. 'high-risk' (≥ 5%). Extent of PLND was analysed using number of nodes yielded at dissection as a continuous variable as well as a categorical variable: Group 1 (limited, 1-4 nodes), Group 2 (intermediate, 5-8 nodes) and Group 3(extensive, ≥9 nodes).

RESULTS

Median follow-up in the overall cohort was 79.7 months and 65% of the total cohort underwent PLND. There were 2402 patients with Briganti risk of LNI < 5% and 1322 with a Briganti risk of LNI ≥5%. At multivariate analysis, only PSA (HR1.01, p < 0.001), extracapsular extension at RP (HR 1.86, p < 0.001), positive surgical margin (HR 1.61, p < 0.001) and positive lymph node on pathology (HR 1.52, p = 0.02) were independently associated with BCR. In the high-risk group, increased nodal yield at PLND was associated with reduction in risk of BCR (HR 0.97, 95%CI 0.95-1.00 p = 0.05, Cochran Mantel Haenszel test, p < 0.05: respectively). In the low-risk group increased number of nodes at PLND did not reduce risk of BCR.

CONCLUSIONS

In this study of extent of PLND at RP, higher nodal yield did not reduce risk of BCR in low-risk men (Briganti risk < 5%), however there was a weak benefit in terms of reduced long-term risk of BCR in high-risk men (Briganti risk ≥5%).

Incidental detection of localized prostate cancer with low PSA by computed tomography scan: A report of two cases

Serum prostate-specific antigen (PSA) levels play an important role in the screening and diagnosis of prostate cancer (PCa). The recommended PSA cut-off in PCa screening is 4 ng/ml. We report two cases of localized PCa with low PSA levels that were incidentally found by computed tomography (CT) performed for another disease.

Pelvic Lymphadenectomy May Not Improve Biochemical Recurrence-Free Survival in Patients with Prostate Cancer Treated with Robot-Assisted Radical Prostatectomy in Japan (The MSUG94 Group)

In this multicenter retrospective cohort study, we aimed to evaluate whether pelvic lymph node dissection (PLND) improved biochemical recurrence (BCR) in patients with prostate cancer (PCa) who underwent robot-assisted radical prostatectomy (RARP) in Japan. A multicenter retrospective cohort study of 3195 PCa patients undergoing RARP at nine institutions in Japan was conducted. Enrolled patients were divided into two groups: those who underwent RARP without PLND (non-PLND group) and those who underwent PLND (PLND group). The primary endpoint was biochemical recurrence-free survival (BRFS) in PCa patients who underwent PLND. We developed a propensity score analysis to reduce the effects of selection bias and potential confounding factors. Propensity score matching resulted in 1210 patients being enrolled in the study. The 2-year BRFS rate was 95.0% for all patients, 95.8% for the non-PLND group, and 94.3% for the PLND group (p = 0.855). For the all-risk group according to the National Comprehensive Cancer Network risk stratification, there were no significant differences between patients who did and did not undergo PLND. Based on the results of the log-rank study, PLND may be unnecessary for patients with PCa undergoing RARP.

Multiparametric MRI-based radiomics model to predict pelvic lymph node invasion for patients with prostate cancer

OBJECTIVE

To identify which patient with prostate cancer (PCa) could safely avoid extended pelvic lymph node dissection (ePLND) by predicting lymph node invasion (LNI), via a radiomics-based machine learning approach.

METHODS

An integrative radiomics model (IRM) was proposed to predict LNI, confirmed by the histopathologic examination, integrating radiomics features, extracted from prostatic index lesion regions on MRI images, and clinical features via SVM. The study cohort comprised 244 PCa patients with MRI and followed by radical prostatectomy (RP) and ePLND within 6 months between 2010 and 2019. The proposed IRM was trained in training/validation set and evaluated in an internal independent testing set. The model's performance was measured by area under the curve (AUC), sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). AUCs were compared via Delong test with 95% confidence interval (CI), and the rest measurements were compared via chi-squared test or Fisher's exact test.

RESULTS

Overall, 17 (10.6%) and 14 (16.7%) patients with LNI were included in training/validation set and testing set, respectively. Shape and first-order radiomics features showed usefulness in building the IRM. The proposed IRM achieved an AUC of 0.915 (95% CI: 0.846-0.984) in the testing set, superior to pre-existing nomograms whose AUCs were from 0.698 to 0.724 (p < 0.05).

CONCLUSION

The proposed IRM could be potentially feasible to predict the risk of having LNI for patients with PCa. With the improved predictability, it could be utilized to assess which patients with PCa could safely avoid ePLND, thus reduce the number of unnecessary ePLND.

KEY POINTS

• The combination of MRI-based radiomics features with clinical information improved the prediction of lymph node invasion, compared with the model using only radiomics features or clinical features. • With improved prediction performance on predicting lymph node invasion, the number of extended pelvic lymph node dissection (ePLND) could be reduced by the proposed integrative radiomics model (IRM), compared with the existing nomograms.

Pelvic Lymph Node Dissection at Radical Prostatectomy for Intermediate Risk Prostate Cancer: Assessing Utility and Nodal Metastases Within a Statewide Quality Improvement Consortium

OBJECTIVE

To assess which patients with intermediate-risk PCa would benefit from a pelvic lymph node dissection (PLND) across the Michigan Urological Surgery Improvement Collaborative, given the discrepancy in recommendations. AUA guidelines for localized prostate cancer (PCa) state that PLND is indicated for patients with unfavorable intermediate-risk and high-risk PCa and can be considered in favorable intermediate-risk patients. NCCN guidelines recommend PLND when risk for nodal disease is ≥2%.

METHODS

Data regarding all robot-assisted radical prostatectomy (RARP) (March 2012-October 2020) were prospectively collected, including patient, and surgeon characteristics. Univariate and multivariate analyses of PLND rate and lymph node involvement (LN+) were performed.

RESULTS

Among 8,591 men undergoing RARP for intermediate-risk PCa, 80.2% were performed with PLND (n = 6883), of which 2.9% were LN+ (n = 198). According to the current AUA risk stratification system, 1.2% of favorable intermediate-risk PCa and 4.7% of unfavorable intermediate-risk PCa demonstrated LN+. There were also differences in the LN+ rates among the subgroups of favorable (0.0%-1.3%), and unfavorable (3.5%-5.0%) categories. Additional factors associated with higher LN+ rates include ≥50% cores positive, ≥35% involvement at any core, and unfavorable genomic classifier result, none of which contribute to the favorable/unfavorable subgroups.

CONCLUSION

These data support PLND at RARP for all patients with unfavorable intermediate-risk PCa. Our data also indicate patients with favorable intermediate-risk prostate cancer at greatest risk for LN+ are those with ≥50% cores positive, ≥35% involvement at any core, and/or unfavorable genomic classifier result.

Predictive ability of prebiopsy magnetic resonance imaging and biopsy for side-specific negative lymph node metastasis at radical prostatectomy

BACKGROUND

Prostate cancer localization is reportedly associated with the laterality of lymph node metastasis. Thus, it may be feasible to predict side-specific lymph node metastasis (LNM) at radical prostatectomy (RP). To investigate whether multiparametric magnetic resonance imaging and biopsy findings can predict side-specific negative LNM and to explore the feasibility of unilateral lymph node dissection (LND) at RP.

METHODS

A total of 500 patients who were diagnosed with prostate cancer with prebiopsy multiparametric magnetic resonance imaging of the prostate and subsequent prostate biopsy and who underwent RP and extended LND without neoadjuvant treatment were enrolled. Multiparametric magnetic resonance imaging, biopsy findings, and LNM were assessed for each side. The negative predictive value (NPV) of multiparametric magnetic resonance imaging or biopsy or both for ipsilateral LNM was examined.

RESULTS

LNM was found in 9.2% (46/500) and 15.6% (28/180) of patients in the overall and high-risk cohorts, respectively. Magnetic resonance imaging and biopsy findings were negative in 408 and 262 sides, respectively, in the overall cohort and 144 and 100 sides, respectively, in the high-risk cohort. The NPVs of magnetic resonance imaging, biopsy, and both for ipsilateral LNM were 98.3%, 98.5%, and 99.1%, respectively, in the overall cohort, and 95.8%, 97.1%, and 97.6%, respectively, in the high-risk cohort.

CONCLUSIONS

Unilateral LND may be indicated based on side-specific LNM risk as assessed by prebiopsy multiparametric magnetic resonance imaging and biopsy.

Comparison of perioperative complications for extended vs standard pelvic lymph node dissection in patients undergoing radical prostatectomy for prostate cancer: a meta-analysis

INTRODUCTION

Pelvic lymph node dissection (PLND) is widely performed for staging in men undergoing radical prostatectomy (RP) for prostate cancer. Our goal was to synthesize all available evidence and data to evaluate perioperative complications for two templates of PLND, standard (sPLND) vs extended (ePLND), at the time of RP in patients with prostate cancer.

METHODS

A meta-analysis was performed on relevant literature about complications during PLND. Pubmed, Scopus, WebofScience, and Cochrane Library were systematically searched through July 2021. Meta-analysis was conducted with both fixed-effects and random-effects models to estimate risk ratios (RRs) between treatments. A subgroup analysis was also conducted based on surgery type - open vs robotic.

RESULTS

13 (1 randomized clinical trial and 12 observational studies) studies published between 1997 and 2019 with a total of 7,036 patients were analyzed. Pooled data showed complications in a random-effects model was lower in the sPLND group than the ePLND group (RR, 0.62; 95% CI 0.40-0.97). In a subgroup analysis, neither the open surgery subgroup nor the robotic surgery subgroup showed significant differences in complication rate between sPLND and ePLND.

CONCLUSION

ePLND is associated with a significantly greater risk of perioperative complication compared to sPLND, but not when comparing these templates performed via a robotic approach. Additional studies comparing the complication rates of sPLND and ePLND when utilizing a robotic approach should be conducted.

Identifying the Candidates Who Will Benefit From Extended Pelvic Lymph Node Dissection at Radical Prostatectomy Among Patients With Prostate Cancer

PURPOSE

The therapeutic effect of extended pelvic lymph node dissection (PLND) in prostate cancer (PCa) patients is still controversial. The aim of this study was to identify the PCa patients who may benefit from extended PLND based on the 2012 Briganti nomogram.

MATERIALS AND METHODS

PCa patients who underwent radical prostatectomy (RP) plus PLND between 2010 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The probability of lymph node invasion (LNI), determined using the 2012 Briganti nomogram, was used to stratify the patients. The endpoints were overall survival (OS) and cancer-specific survival (CSS). Propensity score matching (PSM) was performed to account for potential differences between patients with and without extended PLND. Univariable and multivariable Cox regression was used to analyze the association between the number of removed nodes (NRN) and survival. Kaplan-Meier analysis was performed to estimate OS and CSS. Extended PLND was defined as NRN >75th percentile.

RESULTS

A total of 27,690 patients were included in the study. NRN was not an independent predictor of OS (p = 0.564). However, in patients with probability of LNI ≥37, multivariable analyses showed that increased NRN was associated with improved OS (hazard ratio [HR] = 0.963; p = 0.002). The 5-y OS rate was significantly higher for patients with NRN ≥12 than those with NRN <12 (94.9% vs. 91.9%, respectively; p = 0.015). In the PSM cohort, among patients with probability of LNI ≥37, multivariable analyses showed that increased NRN was associated with improved OS (HR = 0.961; p = 0.004). In addition, the 5-y OS rate was significantly higher for patients with NRN ≥12 than those with NRN <12 (94.9% vs. 89.8%, respectively; p = 0.002). However, NRN was not an independent predictor of CSS in any LNI risk subgroup (all p >0.05).

CONCLUSION

Extensive PLND might be associated with improved survival in PCa patients with a high risk of LNI, which supports the use of extended PLND in highly selected PCa patients. The results need to be validated in prospective studies with long-term follow-up.

Pelvic lymph node dissection in high-risk prostate cancer

INTRODUCTION

The therapeutic role of pelvic lymph node dissection (PLND) in prostate cancer (PCa) is unknown due to absence of randomized trials.

OBJECTIVE

to present a critical review on the therapeutic benefits of PLND in high risk localized PCa patients.

MATERIALS AND METHODS

A search of the literature on PLND was performed using PubMed, Cochrane, and Medline database. Articles obtained regarding diagnostic imaging and sentinel lymph node dissection, PLND extension, impact of PLND on survival, PLND in node positive "only" disease and PLND surgical risks were critically reviewed.

RESULTS

High-risk PCa commonly develops metastases. In these patients, the possibility of presenting lymph node disease is high. Thus, extended PLND during radical prostatectomy may be recommended in selected patients with localized high-risk PCa for both accurate staging and therapeutic intent. Although recent advances in detecting patients with lymph node involvement (LNI) with novel imaging and sentinel node dissection, extended PLND continues to be the most accurate method to stage lymph node disease, which may be related to the number of nodes removed. However, extended PLND increases surgical time, with potential impact on perioperative complications, hospital length of stay, rehospitalization and healthcare costs. Controversy persists on its therapeutic benefit, particularly in patients with high node burden.

CONCLUSION

The impact of PLND on biochemical recurrence and PCa survival is unclear yet. Selection of patients may benefit from extended PLND but the challenge remains to identify them accurately. Only prospective randomized study would answer the precise role of PLND in high-risk pelvis confined PCa patients.

External validation of the Briganti 2019 nomogram to identify candidates for extended pelvic lymph node dissection among patients with high-risk clinically localized prostate cancer

Background

We aimed to establish an external validation of the Briganti 2019 nomogram in a Japanese cohort to preoperatively evaluate the probability of lymph node invasion in patients with high-risk, clinically localized prostate cancer.

Methods

The cohort consisted of 278 patients with prostate cancer diagnosed using magnetic resonance imaging-targeted biopsy who underwent radical prostatectomy and extended pelvic lymph node dissection from 2012 to 2020. Patients were rated using the Briganti 2019 nomogram, which evaluates the probability of lymph node invasion. We used the area under curve of the receiver operating characteristic analysis to quantify the accuracy of the nomogram.

Results

Nineteen (6.8%) patients had lymph node invasion. The median number of lymph nodes removed was 18. The area under the curve for the Briganti 2019 was 0.71. When the cutoff was set at 7%, 84 (30.2%) patients with extended pelvic lymph node dissection could be omitted, and only 1 (1.2%) patient with lymph node invasion would be missed. Sensitivity, specificity, and negative predictive values at the 7% cutoff were 94.7, 32.0, and 98.8%, respectively.

Conclusion

This external validation showed that the Briganti 2019 nomogram was accurate, although there may still be scope for individual adjustments.

A narrative review of pelvic lymph node dissection in prostate cancer

Pelvic lymph node dissection (PLND) is an important component in the staging and prognostication of prostate cancer. We performed a narrative review to assess the literature surrounding PLND: (I) the current guideline recommendations and contemporary utilization, (II) the calculation of patient-specific risk to perform PLND using available nomograms, (III) to review the extent of dissection, and its associated outcomes and complications. Due to the improved lymph node yield, better staging, and theoretical improvement in the control of micro-metastatic disease, guidelines have supported the use of (extended-) PLND in patients deemed to be at intermediate or high risk of lymph node involvement (often at a threshold of 5% on modern risk nomograms). However, in practice, real-world utilization of PLND varies considerably due to multiple reasons. Conflicting evidence persists with no clear oncological benefit to PLND, and a small, but important, risk of morbidity. Complications are rare, but include lymphoceles; thromboembolic events; and more rarely, obturator nerve, vascular, and ureteric injury. Furthermore, changing disease incidence and stage migration in the context of earlier detection overall have led to a decreased risk of nodal disease. The trade-offs between the benefits, harms, and risk tolerance/threshold must be carefully considered between each patient and their clinician.