Possible role of template-based lymphadenectomy in reducing the risk of regional node recurrence after nephroureterectomy in patients with renal pelvic cancer

Oncological outcomes of retroperitoneal lymph node dissection during retroperitoneal laparoscopic radical nephroureterectomy for renal pelvic or upper ureteral tumors: Matched-pair analysis

OBJECTIVES

To investigate the oncological outcomes and recurrence patterns of clinically node-negative patients with renal pelvic and/or upper or middle ureteral tumors after a template-based retroperitoneal lymph node dissection (RPLND) in conjunction with retroperitoneal laparoscopic radical nephroureterectomy (LRNU).

METHODS

A total of 283 patients who received LRNU with and without RPLND at three Japanese institutions were enrolled. The template of RPLND included the renal hilar and paraaortic lymph nodes (LNs) (left side) and renal hilar, paracaval, retrocaval, and intra-aortocaval LNs (right side). The LNs and kidneys were removed en bloc. The primary endpoint was set as recurrence-free survival. All RPLND cases were matched one-to-one with no RPLND cases using a propensity score matching approach, and 47 matched pairs were included in analyses.

RESULTS

Compared to the control group, significant differences were not observed in the RPLND group in terms of operation time, blood loss, postoperative complication rate, and pathological findings. The estimated five-year recurrence-free survival was significantly higher in the RPLND group (86.8%) compared to the group without RPLND (64.2%) (p = 0.014). The estimated five-year cancer-specific survival showed a similar tendency; however, it did not reach a statistically significant difference (87.5% vs 71.3%, respectively; p = 0.168). As for the first recurrence site, the RPLND group showed a lower incidence of distant recurrence, while a significant difference was not observed in the rate of regional LN recurrence.

CONCLUSION

This study suggests that a template-based RPLND in conjunction with retroperitoneal LRNU efficiently improves the recurrence-free survival by reducing distant recurrences.

Prospective Clinical Trial of the Oncologic Outcomes and Safety of Extraperitoneal Laparoscopic Extended Retroperitoneal Lymph Node Dissection at Time of Nephroureterectomy for Upper Tract Urothelial Carcinoma

Purpose

To determine the safety and feasibility of extraperitoneal laparoscopic extended lymph node dissection (LND) at the time of extraperitoneal laparoscopic radical nephroureterectomy (RNU).

Materials and Methods

Between May 2018 and March 2019, 39 patients with upper tract urothelial carcinoma (UTUC) received extraperitoneal laparoscopic RNU and concomitant extraperitoneal laparoscopic extended LND. All patients were followed for at least 90 days. Perioperative and pathological data including nodal status and perioperative complications were collected.

Results

Among all 39 patients, 12 patients had pT1, 6 had pT2, 20 had pT3 disease, and 1 had T4 disease. The median (range) lymph node count was 10 (5–22), with 8 patients having pathologically proven lymph node metastasis. The median (range) operating time was 225 (165–430) min, and the median estimated blood loss was 200 (60–800) ml. The median postoperative hemoglobin loss was 1.6 (0–4.2) g/dl. The median (range) postoperative hospital stays were 6 (3–26) days. Overall, 7 patients experienced minor (Clavien Grade I–II) postoperative complications with five patients having Clavien Grade I complications and two patients having Clavien Grade II complications. No major complication (Clavien grade III–IV) occurred. With a median follow-up of 38 months, a total of 8 patients (20.5%) developed local or distant recurrence and no regional LNs where extended LND were performed had recurrence.

Conclusions

The present prospective study demonstrated that extraperitoneal laparoscopic extended LND during extraperitoneal laparoscopic RNU for UTUC is a feasible and safe procedure which provides minimal invasion, rapid recovery, and potentially lower risk of regional LN recurrence. Larger prospective clinical trials with survival endpoints are needed to further determine its potential therapeutic benefits.

Trial Registration

ClinicalTrials.gov identifier NCT 03544437 www.clinicaltrials.gov

Role of lymph node dissection at the time of open or minimally invasive nephroureterectomy

Unlike urothelial carcinoma of the bladder, there is no guideline-based consensus on whether a lymph node dissection (LND) should be performed at the time of radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). Variable lymphatic drainage based on primary tumor location, lack of prospective trials, and difficulties in developing a risk-adapted approach to LND for UTUC are all challenges to the development of an established approach. The UTUC literature consists of an evidence pool that has historically been limited to single-institution series with heterogenous inclusion criteria for LND and variable LND templates. Areas of controversy exist regarding migration to the great vessel LN beds for mid and distal tumors. A lack of template standardization limits the interpretation of studies relative to one another and a lack of uniformity in reporting templates may lead to inaccuracies in the estimation of lymph node metastasis landing sites. Most clinicians agree that there is a staging benefit to LND for UTUC. Although the data is somewhat heterogenous, it demonstrates a prognostic and staging benefit to LND in higher stages of UTUC. Unlike the staging benefits provided by LND for UTUC, the therapeutic benefits are not as clearly established. Several studies have evaluated differences in cancer-specific survival (CSS) and demonstrated LND to be an independent predictor of CSS when compared to patients not undergoing LND. However, this finding is not consistent across all studies and the literature is again limited by inclusion heterogeneity and inconsistent or lack or template-based resections. LND for UTUC at the time of RNU is a safe and feasible procedure that seems to especially benefit patients with muscle-invasive or locally advanced disease. Prospective, randomized studies with strict inclusion criteria and defined anatomic templates are needed to definitely characterize the role of LND for UTUC.

The nephroureterectomy: a review of technique and current controversies

The nephroureterectomy (NU) is the standard of care for invasive upper tract urothelial carcinoma (UTUC) and has been around for well over one hundred years. Since then new operative techniques have emerged, new technologies have developed, and the surgery continues to evolve and grow. In this article, we review the various surgical techniques, as well as present the literature surrounding current areas of debate surrounding the NU, including the lymphatic drainage of the upper urinary tract, management of UTUC involvement with the adrenals and caval thrombi, surgical management of the distal ureter, the use of intravesical chemotherapy as well as perioperative systemic chemotherapy, as well as various outcome measures. Although much has been studied about the NU, there still is a dearth of level 1 evidence and the field would benefit from further studies.

Survival Benefits Based on the Number of Lymph Nodes Removed during Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma: Systematic Review and Meta-Analysis

The role of lymph node dissection (LND) is still controversial for upper tract urothelial carcinoma (UTUC), and there are no guidelines regarding its use. This study was conducted to find a higher level of evidence for the survival benefits based on the number of LNs removed during radical nephroureterectomy (RNUx) through a systematic review and meta-analysis. We included studies comparing patients who underwent LND during RNUx for UTUC. We searched the major electronic databases (Pubmed, Embase^®, and Scopus^®) and conducted manual searches of the electronically available abstracts of the major international urology cancer meetings [American Society of Clinical Oncology (ASCO), American Urological Association (AUA), and Eropean Association of Urology (EAU)] prior to April 2019 using grouped terms of nephroureterectomy (nephroureterectom*) and lymph node excision (lymphadenectomy; lymph + node*; lymph* + metasta*) with variations in the terms. Study selection, data collection, and risk of bias assessment were performed by two independent authors (A and B). Six retrospective case-control studies included a total of 33,944 patients who underwent RNUx for UTUC, 5071 of whom underwent LND and were finally included in the meta-analysis. The pooled hazard ratio (HR) in these studies revealed that an increased number of LNs removed during RNUx was associated with improved cancer-specific survival (CSS) in patients with UTUC (HR = 0.95, 95% CI: 0.91–0.99; p = 0.07). In addition, increased numbers of LNs removed were associated with improved overall survival (OS) in pN0 patients. However, in pN+ patients, the number of LNs removed showed no survival benefit on CSS, overall survival (OS), or progression-free survival (PFS). Higher numbers of LNs removed during RNUx were associated with improved survival outcomes in patients with UTUC. This study confirmed that LND also has oncological benefits in UTUC patients. Although still a controversial topic, meticulous LND must be considered, and efforts should be made to eliminate as many LNs as possible when administering RNUx for UTUC, especially in patients without clear evidence of LN metastasis.

Lymph node dissection during nephroureterectomy: Establishing the existing evidence based on a review of the literature

Abstract Objective: To determine the role of lymph node dissection (LND) in the treatment of upper tract transitional cell carcinoma (UTTCC), as the role of LND along with nephroureterectomy in treating UTTCC is unclear and several retrospective studies have been published on this topic with conflicting results.

Methods: The Medical Literature Analysis and Retrieval System Online (MEDLINE), the Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of Controlled Trials database (CENTRAL), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Clinicaltrials.gov, Google Scholar, and individual urological journals, were searched for all studies investigating the role of LND in the treatment of UTTCC. Of the studies identified, those that met inclusion criteria were included in this review.

Results: In all, 27 studies were included in this review, with 9303 patients who underwent LND. No randomised controlled trials (RCTs) were identified. Tumours were located in the renal pelvis in 62% of patients, in the ureter in 35.5%, and multifocal in 2.3%. In total: 77.1% were LN-negative and 22.9% had LN metastasis. For all patients undergoing LND, the 5-year recurrence-free survival (RFS) and cancer-specific survival (CSS) rates were 27–65.4% and 32.3–95%, respectively. For patients who underwent a LND in accordance with a standardised anatomical template, the 5-year RFS and CSS rates were 84.3–93% and 83.5–94%, respectively.

Conclusion: LND may provide a survival benefit in patients undergoing nephroureterectomy for UTTCC, particularly if following a standardised anatomical template and in those patients with muscle-invasive disease; however, a prospective RCT is required to confirm this.

Abbreviations: CSS: cancer-specific survival; LN(D): lymph node (dissection); MeSH: Medical Subject Headings; OS: overall survival; pT: pathological T stage; RCT: randomised controlled trial; RFS: recurrence-free survival; UTTCC: upper tract TCC

Association between demographic factors and prognosis in urothelial carcinoma of the upper urinary tract: a systematic review and meta-analysis

We aimed to assess the prognostic significance of demographic factors, including age, sex, performance status, smoking status, obesity, and race in upper urinary tract urothelial carcinoma (UTUC) patients treated with radical nephroureterectomy through a systematic review and meta-analysis. We conducted PubMed search for all articles published until December 2014 according to Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Survival outcomes of interest were intravesical recurrence (IVR) free survival, progression free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). Seventy-nine studies, including numbers of subjects ranging from 24 to 9899, met the inclusion criteria. Advanced age was significantly associated with worse PFS [hazard ratio (HR) 1.01] and OS (HR 1.05). The significant predictors of CSS were age (HR 1.02) and performance status (HR 1.35). Female gender (HR 0.81) and smoking (HR 1.38) were the significant predictors only for IVR free survival. No significant associations with survival outcomes were observed in obesity and race. Our study reveals that age is one of the most important demographic predictor of survival in UTUC. Also, male gender, poor performance status, and smoking are also significantly related to worse survival outcomes. However, large well-designed prospective studies are required to investigate the precise prognostic significance of demographics.

Lymphadenectomy for Muscle-Invasive Bladder Cancer and Upper Tract Urothelial Cell Carcinoma

There are currently no reported randomized trials that characterize the staging or therapeutic benefit of performing a lymph node dissection in either bladder cancer or upper tract urothelial carcinoma. Several unanswered questions remain in this domain focused on the indications and patient selection for pelvic lymph node dissection, extent of dissection, its impact on outcome, and potential risks. However, the results of observational studies suggest that the burden of metastasis is high in both diseases when muscle invasive and performing a lymphadenectomy can provide prognostic information and yield therapeutic benefit.

Anatomical templates of lymph node dissection for upper tract urothelial carcinoma: a systematic review of the literature

INTRODUCTION

Indications and techniques of lymph node dissection (LND) for upper tract urothelial carcinoma (UTUC) are still controversial. Areas covered: In this study, a systematic review of the English-language literature was performed up to 1 July 2016 using the Medline, Scopus, Cochrane Library and Web of Sciences databases to provide a detailed overview of the most commonly dissected surgical templates of LND for UTUC according to laterality and location of the tumor. Overall, sixteen studies were analyzed. Based on the shared experiences in the scientific literature, the LND template typically included: for right-sided tumors of the renal pelvis, upper third and middle third of the ureter, the renal hilar, paracaval, precaval and retrocaval nodes, while for left-sided tumors the renal hilar, paraaortic and preaortic nodes. For tumors of the lower ureter, an extended pelvic LND was performed in most cases; however, the paracaval, paraaortic or presacral nodes were dissected in selected series. Expert commentary: LND is not routinely performed at the time of surgery for UTUC and both indication and extent of LND vary among surgeons and institutions. Future high-quality studies are needed to define the most accurate LND templates and to assess their oncological efficacy and surgical morbidity.

Contemporary role of lymph node dissection at the time of radical nephroureterectomy for upper tract urothelial carcinoma

PURPOSE

To review the contemporary data on the role of lymph node dissection (LND) at the time of radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC).

METHODS

A computerized bibliographic search using the following protocol ("Nephroureterectomy") AND ("Lymphadenectomy" OR "Lymph node" OR "Lymphatic") was performed in MEDLINE to identify all original and review articles that addressed the role of LND for UTUC.

RESULTS

Regional lymph node (LN) boundaries of UTUC have been recently investigated in mapping studies to propose anatomic templates of LND according to the laterality and location of primary tumor. Although these anatomic templates remained poorly described, most reports supported the staging benefit of LND that allowed for risk stratification of patients with (pN+) or without (pN0) LN metastases from those who did not undergo such a procedure (pNx). In addition, the therapeutic benefit of LND at the time of RNU was supported by better oncological outcomes obtained after complete LND when compared to incomplete or no LND, especially in the group of patients with advanced disease. The number of LNs removed was also correlated with both, more accurate staging and greater cancer-specific survival after LND, whose feasibility and safety have been validated in prospective studies.

CONCLUSIONS

Despite mostly based on data with level of evidence 3, our comprehensive review of the literature supports the staging and therapeutic benefits of LND at the time of RNU for UTUC, which are particularly significant for patients with muscle-invasive or locally advanced disease.

Therapeutic role of template-based lymphadenectomy in urothelial carcinoma of the upper urinary tract

Lymphadenectomy for urothelial carcinoma of the upper urinary tract has attracted the attention of physicians. The mapping study of lymphatic spread has shown that a relatively wide area should comprise the regional nodes for tumors of the right renal pelvis or the right upper two-thirds of the ureter. A prospective study showed that an anatomical template-based lymphadenectomy significantly improved patient survival in tumors of the renal pelvis. This benefit was more evident for patients with pT2 stage tumors or higher. The risk of regional node recurrence is significant reduced by template-based lymphadenectomy, which is likely to be associated with improved patient survival. The removal of lymph node micrometastases is assumed to be the reason for therapeutic benefit following lymphadenectomy. The number of resected lymph nodes can be used to assess the quality of lymphadenectomy, but not to determine the extent of lymphadenectomy. The guidelines currently recommend lymphadenectomy for patients with muscle-invasive disease, even though the current recommendation grades are still low. The present limitation of lymphadenectomy is the lack of standardization of the extent of lymphadenectomy and the randomized trials. Further studies are warranted to collect the evidence to support lymphadenectomy.

Patterns of Lymphatic Metastases in Upper Tract Urothelial Carcinoma and Proposed Dissection Templates

PURPOSE

Information on patterns of lymph node metastases for upper tract urothelial carcinoma is sparse. We investigated patterns of lymph node metastases in upper tract urothelial carcinoma.

MATERIALS AND METHODS

We performed a retrospective multi-institutional study of 73 patients with N+M0 upper tract urothelial carcinoma who underwent template lymphadenectomy during nephroureterectomy. Anatomical locations of tumor, and number of lymph nodes removed and positive lymph nodes were analyzed and descriptive statistics were performed.

RESULTS

On the right side the 20 renal pelvis tumors had lymph node metastases to the hilum in 22.1% of cases, and to paracaval, retrocaval and interaortocaval regions in 44.1%, 10.3% and 20.6%, respectively. The 10 proximal ureter tumors had lymph node metastases to the hilum in 46.2% of cases, and to paracaval and retrocaval regions in 46.2% and 7.7%, respectively. The 2 distal ureter tumors had lymph node metastases equally to the paracaval and pelvic regions. On the left side the 24 renal pelvis tumors had lymph node metastases to the hilum region in 50.0% of cases and to the para-aortic region in 30.0%. The 8 proximal ureter tumors had lymph node metastases to the hilum region in 36.4% of cases and the para-aortic region in 63.6%. The 5 mid ureter tumors had lymph node metastases to the para-aortic, common iliac and internal iliac regions in 40%, 40% and 20% of cases, respectively. The 4 distal ureter tumors had lymph node metastases to the para-aortic, common iliac, external iliac and internal iliac regions in 33.3%, 33.3%, 16.7% and 16.7% of cases, respectively. Interaortocaval involvement from both sides as well as out of field lymph node metastases appeared to occur secondarily. Consolidated templates were constructed based on the available data.

CONCLUSIONS

Upper tract urothelial carcinoma has characteristic patterns of lymph node metastases depending on the side and anatomical location of the primary tumor, including right-to-left migration and involvement of interaortocaval nodes in the setting of proximal disease. Standardized dissection templates should be prospectively evaluated in multicenter trials to assess morbidity and potential clinical benefit.

Lymphadenectomy for testicular, penile, upper tract urothelial and urethral cancers

PURPOSE OF REVIEW

The lymph node dissection (LND) is an integral component of many oncologic surgeries. Better understanding of each cancer's behaviour and improvements in surgical techniques necessitate a critical analysis of lymph node disease and the optimal LND template. This review will focus on updates in managing lymph node disease in testicular, penile, upper tract urothelial and urethral cancer.

RECENT FINDINGS

For testicular and penile cancer, advances have focused on reducing the morbidity associated with the standard templates of dissection while maintaining oncologic efficacy. For upper tract urothelial carcinoma, data continue to be mixed regarding the need for a LND, though it does seem to benefit patients with advanced tumours. Little is known regarding the optimal LND template for urethral cancer.

SUMMARY

A thorough LND has an established diagnostic and therapeutic role in testicular and penile cancer. For upper tract urothelial carcinoma, the role of an LND remains controversial, though emerging evidence points to an association with improved outcomes. Due to the rarity of urethral cancer, there are no standard LND templates, though excising clinically positive nodes is recommended. For all these cancers, more sophisticated risk stratification based upon clinical and pathologic factors has helped determine which patients require an LND and how to best manage these patients after surgery.