Pelvic Lymph Node Dissection in Prostate Cancer: The Mystery Is Taking Shape

Use of intraoperative fluorescence to enhance robot-assisted radical prostatectomy

Robot-assisted radical prostatectomy has become the standard of care for the removal of localized prostate cancer. Positive outcomes depend upon the precise removal of the prostate and associated tissue without damage to nearby structures. This process can be aided by fluorescence-guided surgery to enhance the visual contrast between different structures. Here the authors have conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify ten investigations into the use of fluorescence-guided surgery in robot-assisted radical prostatectomy. These studies used fluorescent tracers to identify structures, including the prostate, neurovascular bundle and lymph nodes. These studies demonstrate the safe and effective use of fluorescence-guided surgery in robot-assisted radical prostatectomy and pave the way for further developments in this field.

Is the Recommendation of a Pelvic Lymphadenectomy in Conjunction with Radical Prostatectomy in Prostate Cancer Patients Justified? Report from a Multidisciplinary Expert Panel Meeting

INTRODUCTION

Pelvic lymphadenectomy (pLA) in prostate cancer (PCa) is one of the most common uro-oncologic surgical procedures. An increased complication rate is accompanied by unproven oncologic benefit. Extent of pLA and mechanisms of metastasis are discussed controversially. We aimed to explore evidence and knowledge gaps in pLA and mechanisms of metastasis in PCa and to develop further steps to clarify oncologic benefits through an expert panel.

METHODS

A multidisciplinary expert meeting was initiated, compiling available facts on pLA and mechanisms of metastasis in PCa. Questions and hypotheses were formulated. The resulting protocol was modeled on priority and consistency in four anonymized voting rounds using the Delphi method (March 2018-June 2018).

RESULTS

The oncologic benefit of pLA in PCa is still unclear. Results of randomized trials (RCTs) are pending. Extent and techniques of pLA are differently applied and inconsistently recommended by the guidelines as well as the indication for pLA. Different growth rates for the primaries and metastases and different survival curves for lymph node and organ metastasis at diagnosis argue against metastasis originating from positive nodes. However, results from clinical and basic research support this opportunity in PCa.

CONCLUSIONS

The RCTs required to clarify the estimated low oncologic benefit of pLA prove to be difficult because of the great effort (e.g., high case number). Establishing a network of treatment centers for implementation of high-quality cohort studies could be an alternative approach. Future studies with larger panels and international participants based on the presented feasibility should be launched to set this process in motion. Until valid data are available, benefits and harms of pLA should be weighted under consideration of low-invasive techniques (e.g., sentinel pLA).

Facility-Level Variation in Pelvic Lymphadenectomy During Radical Prostatectomy and Effect on Overall Survival in Men with High-Risk Prostate Cancer

PURPOSE

This study was designed to examine facility-level variation in the extent of pelvic lymphadenectomy and to determine whether more extensive lymphadenectomy is associated with a survival benefit among men with localized high-risk prostate cancer.

METHODS

Using data from the National Cancer Data Base, we identified 13,652 men with a high predicted probability of 10-year survival (≤ 65 years of age and Charlson Comorbidity Index score of 0) who underwent radical prostatectomy at 1023 facilities for biopsy-confirmed localized high-risk prostate cancer diagnosed between January 2004 and December 2011. Multilevel, multinomial logistic regression was fitted to predict facility-level probability of receiving different extents of lymphadenectomy. Inverse probability of treatment weighting-adjusted Cox regression model with Bonferroni correction was fitted to compare risk of overall mortality.

RESULTS

Overall, 11,284 (82.7%), 1601 (11.7%), and 767 (5.6%) men who underwent radical prostatectomy underwent concomitant none/limited lymphadenectomy (0-9 lymph nodes), standard lymphadenectomy (10-16 lymph nodes), and extended lymphadenectomy (≥ 17 lymph nodes), respectively. Extended lymphadenectomy was not associated with a survival benefit relative to standard lymphadenectomy (hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.48-1.23; p = 0.4) nor no/limited lymphadenectomy (HR 0.77, 95% CI 0.87-2.20; p = 0.29) at a median follow-up of 83.3 months. Risk-adjusted facility-level predicted probabilities of extended, standard, or no/limited lymphadenectomy ranged from 0.01 to 52.6%, 3.3-53.3%, and 17.8-96.3%, respectively.

CONCLUSIONS

We found significant facility-level variation in the extent of pelvic lymphadenectomy during radical prostatectomy despite no apparent survival benefit associated with more extensive lymphadenectomy. Further prospective data are needed to reevaluate the role of lymphadenectomy in the management of clinically localized prostate cancer.

Eliminating microscopic lymph node metastasis by performing pelvic lymph node dissection during radical prostatectomy for prostate cancer

The oncological benefit of pelvic lymph node dissection (PLND) for prostate cancer (PCa) remains unclear. The therapeutic effect of PLND on the elimination of microscopic metastases during radical prostatectomy (RP) for PCa was examined in the current study. A total of 348 Japanese patients with high- or intermediate-risk PCa without lymph node metastasis, who underwent antegrade RP at the Kyushu Cancer Center (Fukuoka, Japan) between August 1998 and May 2013 were retrospectively analyzed. The patients were divided into the standard (obturator + internal iliac nodes) group and the expanded (standard + additional nodes) group according to the extent of PLND. Preoperative and postoperative characteristics were also analyzed to determine the factors associated with prostate-specific antigen (PSA) failure. Standard and expanded PLND were performed in 70.9% (247/348) and 29.1% (101/348) of cases, respectively. The results revealed that preoperative PSA levels were the only marked difference between the two groups. No differences were observed in the other preoperative and postoperative characteristics. Furthermore, the rate of PSA recurrence in each group did not differ to a statistically significant extent (P=0.3622). Reducing the area of dissection from expanded PLND to standard PLND significantly reduced the number of dissected lymph nodes (P<0.0001). Additionally, the PSA level, clinical tumor stage, Gleason score of the biopsy specimen, pathological tumor stage and extent of PLND were all associated with PSA recurrence, as determined via multivariate Cox hazards regression analysis (P=0.0177, P=0.0023, P=0.0027, P<0.0001 and P=0.0164, respectively). In high- and intermediate-risk patients without lymph node metastasis, a greater number of lymph nodes were dissected when the extent of dissection was greater. Furthermore, the extent of PLND was a significantly associated with PSA failure. The results indicated that PLND exerted a therapeutic effect by eliminating microscopic pelvic lymph node metastases that were not detected by routine pathological examinations.

Hospital readmissions after limited vs. extended lymph node dissection during open and robot-assisted radical prostatectomy

PURPOSE

Differences exist concerning when and how to perform lymph node dissection (LND) during radical prostatectomy due to lack of high-grade evidence to its safety and efficacy. We aimed to compare readmission rates between limited and extended LND during open radical prostatectomy (ORP) and robot-assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

We conducted a prospective trial of 3,706 eligible patients comparing ORP vs. RARP (LAPPRO). Six hundred and twenty-seven underwent concomitant LND. Data were retrieved for readmissions within 90 days from surgery from the Swedish Patient Registry. Causes for readmissions were classified according to the modified Clavien-Dindo classification system. We estimated risks for readmission stratified by type of LND and surgical approach.

RESULTS

We recorded 107 readmissions in 90 patients. The overall readmission rate was 14% (90/627). In the open group, extended LND had a higher, but not statistically significant readmission rate of 18% compared to 11% after limited LND (95%CI 0.87-3.01). In the robot-assisted group, readmissions after extended LND did not differ from limited LND (15% vs. 18%, 95%CI 0.49-1.61). RARP with limited LND showed a higher risk for any (RR 1.98, 95%CI [1.02-3.81]) as well as Clavien-Dindo grade 1 to 2 readmissions (RR 2.49, 95%CI [1.10-5.63]) compared to open approach with limited LND. Robot-assisted extended LND reduced the risk for Clavien-Dindo grade 3 to 5 complications leading to readmissions compared to the open approach by 59% (RR 0.41, 95%CI [0.19-0.87]).

CONCLUSIONS

The risk for hospital readmission was similar when performing limited or extended LND during a radical prostatectomy. Robot-assisted technique for performing extended LND may decrease the risk for severe complications.

Difference in Frequency and Distribution of Nodal Metastases Between Intermediate and High Risk Prostate Cancer Patients: Results of a Superextended Pelvic Lymph Node Dissection

Objectives: To evaluate the frequency and distribution of pelvic nodes metastases, in intermediate-high risk prostate cancer (PCa) patients (pts), who underwent open radical prostatectomy (ORP) and superextended pelvic lymph node dissection (sePLND). Patients and Methods: We retrospectively evaluated 630 consecutive pts with clinically localized, intermediate-high risk PCa, treated with ORP and sePLND from 2009 to 2016 at a single institution. The sePLND always removed all nodal/fibro-fatty tissue of the internal iliac, external iliac, obturator, common iliac, and presacral regions. Results: Positive lymph nodes (LN+) were found in 133 pts (21.1%). The median number of removed nodes and LN+ was 25 and 1, respectively. LN+ were found in 64 (48.1%), 58 (43.6%), 53 (39.8%), 16 (12%), and 20 (15%) pts and were present as a single site in 27 (20.3%), 22 (16.5%), 20 (15%), 0, and 6 (4.5%) cases in the internal iliac, external iliac, obturator, common iliac, and presacral chain, respectively. An ePLND would have correctly staged 127 (95%) pts but removed all LN+ in only 97 (73%) pts. Presacral nodes harbored LN+ in 20 patients. Among them, 18 were high-risk patients. Moreover, all but 1 pts with common iliac LN+ were in high risk group. Conclusions: These results suggest that removal of presacral and common iliac nodes could be omitted in intermediate risk pts. However, a PLND limited to external iliac, obturator, and internal iliac region may be adequate for nodal staging purpose, but not enough accurate if we aim to remove all possible site of LN+ in high risk pts.

The Benefits and Harms of Different Extents of Lymph Node Dissection During Radical Prostatectomy for Prostate Cancer: A Systematic Review

CONTEXT

There is controversy regarding the therapeutic role of pelvic lymph node dissection (PLND) in patients undergoing radical prostatectomy for prostate cancer (PCa).

OBJECTIVE

To systematically review the relevant literature assessing the relative benefits and harms of PLND for oncological and non-oncological outcomes in patients undergoing radical prostatectomy for PCa.

EVIDENCE ACQUISITION

MEDLINE, MEDLINE In-Process, Embase, and the Cochrane Central Register of Controlled Trials were searched up to December 2015. Comparative studies evaluating no PLND, limited, standard, and (super)-extended PLND that reported oncological and non-oncological outcomes were included. Risk-of-bias and confounding assessments were performed. A narrative synthesis was undertaken.

EVIDENCE SYNTHESIS

Overall, 66 studies recruiting a total of 275,269 patients were included (44 full-text articles and 22 conference abstracts). Oncological outcomes were addressed by 29 studies, one of which was a randomized clinical trial (RCT). Non-oncological outcomes were addressed by 43 studies, three of which were RCTs. There were high risks of bias and confounding in most studies. Conflicting results emerged when comparing biochemical and clinical recurrence, while no significant differences were observed among groups for survival. Conversely, the majority of studies showed that the more extensive the PLND, the greater the adverse outcomes in terms of operating time, blood loss, length of stay, and postoperative complications. No significant differences were observed in terms of urinary continence and erectile function recovery.

CONCLUSIONS

Although representing the most accurate staging procedure, PLND and its extension are associated with worse intraoperative and perioperative outcomes, whereas a direct therapeutic effect is still not evident from the current literature. The current poor quality of evidence indicates the need for robust and adequately powered clinical trials.

PATIENT SUMMARY

Based on a comprehensive review of the literature, this article summarizes the benefits and harms of removing lymph nodes during surgery to remove the prostate because of PCa. Although the quality of the data from the studies was poor, the review suggests that lymph node removal may not have any direct benefit on cancer outcomes and may instead result in more complications. Nevertheless, the procedure remains justified because it enables accurate assessment of cancer spread.

Laparoscopic sentinel lymph node dissection in prostate cancer patients: the additional value depends on preoperative data

AIM

In intermediate- or high-risk prostate cancer (PC) patients, to avoid extended pelvic lymph node dissection (ePLND), the updated Briganti nomogram is recommended with the cost of missing 1.5 % of patients with lymph node invasion (LNI). Is it possible to reduce the percentage of unexpected LNI patients (nomogram false negative)? We used the isotopic sentinel lymph node (SLN) technique systematically associated with laparoscopic ePLND to assess the potential value of isotopic SLN method to adress this point.

METHODS

Two hundred and two consecutive patients had procedures with isotopic SLN detection associated with laparoscopic ePLND for high or intermediate risk of PC. The area under the curve (AUC) of the receiver operating characteristics (ROC) analysis was used to quantify the accuracy of different models as: the updated Briganti nomogram, the percentage of positive cores, and an equation of the best predictors of LNI. We tested the model cutoffs associated with an optimal negative predictive value (NPV) and the best cutoff associated with avoiding false negative SLN detection, in order to assist the clinician's decision of when to spare ePLND.

RESULTS

LNI was detected in 35 patients (17.2 %). Based on preoperative primary Gleason grade and percentage of positive cores, a bivariate model was built to calculate a combined score reflecting the risk of LNI. For the Briganti nomogram, the 5 % probability cutoff avoided ePLND in 53 % (108/202) of patients, missing three LNI patients (8.6 %), but all were detected by the SLN technique. For our bivariate model, the best cutoff was <10, leaving no patient with LNI due to positive SLN detection (four patients = 11.4 %), and avoiding ePLND in 52 % (105/202) of patients.

CONCLUSION

For patients with a low risk of LNI determined using the updated Briganti nomogram or bivariate model, SLN technique could be used alone for lymph node staging in intermediate- or high-risk PC patients.

Extended lymph node dissection in robotic radical prostatectomy: Current status

Introduction:

The role and extent of extended pelvic lymph node dissection (ePLND) during radical prostatectomy (RP) for prostate cancer patients remains unclear.

Materials and Methods:

A PubMed literature search was performed for studies reporting on treatment regimens and outcomes in patients with prostate cancer treated by RP and extended lymph node dissection between 1999 and 2013.

Results:

Studies have shown that RP can improve progression-free and overall survival in patients with lymph node-positive prostate cancer. While this finding requires further validation, it does allow urologists to question the former treatment paradigm of aborting surgery when lymph node invasion from prostate cancer occurred, especially in patients with limited lymph node tumor infiltration. Studies show that intermediate- and high-risk patients should undergo ePLND up to the common iliac arteries in order to improve nodal staging.

Conclusions:

Evidence from the literature suggests that RP with ePLND improves survival in lymph node-positive prostate cancer. While studies have shown promising results, further improvements and understanding of the surgical technique and post-operative treatment are required to improve treatment for prostate cancer patients with lymph node involvement.