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

Modern Kidney-Sparing Management of Upper Tract Urothelial Carcinoma

PURPOSE

To review the latest evidence on the modern techniques and outcomes of kidney-sparing surgeries (KSS) in patients with upper tract urothelial carcinoma (UTUC).

METHODS

A comprehensive literature search on the study topic was conducted before 30 April 2023 using electronic databases including PubMed, MEDLINE, and EMBASE. A narrative overview of the literature was then provided based on the extracted data and a qualitative synthesis of the findings.

RESULTS

KSS is recommended for low- as well as select high-risk UTUCs who are not eligible for radical treatments. Endoscopic ablation is a KSS option that is associated with similar oncological outcomes compared with radical treatments while preserving renal function in well-selected patients. The other option in this setting is distal ureterectomy, which has the advantage of providing a definitive pathological stage and grade. Data from retrospective studies support the superiority of this approach over radical treatment with similar oncological outcomes, albeit in select cases. Novel chemoablation agents have also been studied in the past few years, of which mitomycin gel has received FDA approval for use in low-risk UTUCs.

CONCLUSION

KSSs are acceptable approaches for patients with low- and select high-risk UTUCs, which preserve renal function without compromising the oncological outcomes.

The Stratification of Positive Lymph Nodes into pN1 and pN2 for Upper Urinary Tract Carcinoma is not Prognostically Significant

The 3^rd-7^th edition of the American Joint Committee on Cancer had 3 categories for positive lymph nodes (pN1-3) in upper urinary tract carcinoma. The 8^th edition removed pN3, defining pN1 as one lymph node with tumor deposit ≤ 2 cm and pN2 as a node with tumor deposit > 2 cm or metastases in multiple nodes. The aim of this study was to assess if the current pN categories impact survival in renal pelvic and ureteral carcinoma. Nephroureterectomies performed at our institution for primary upper urinary tract carcinoma between 2010-2019 were reviewed. Lymphadenectomy was performed in 73.3% of cases (151/206, median 9 nodes). Eighty-one (53.6%) patients were deceased at last review [pN0, 53 (44.5%); pN1-2, 28 (87.5%)]. There was no difference in overall or recurrence free survival between pN1 and pN2 with 5-year overall survival (95% confidence interval) of pN0, 60.7% (52.0-70.8%); pN1, 15.4% (4.3-35.2%); and pN2, 21.1% (8.8-40.3%). The metastatic deposit size threshold of 2 cm, number of positive lymph nodes, as well as extranodal extension did not correlate with overall or recurrence free survival. As such, pN1 and pN2 were grouped together with a 5-year overall survival of 18.8% (9.12-28.6%). The current stratification of upper urinary tract carcinoma into pN1 and pN2 does not provide prognostic information, and both yield a stage IV classification, regardless of pT or pM category. Therefore, we recommend further simplification of pN classification into one category for regional lymph node metastasis, irrespective of lymph node deposit size or number of positive lymph nodes.

Robotic and 3D laparoscopic radical nephroureterectomy with en bloc specimen excision (kidney, ureter, bladder cuff excision and extended lymphadenectomy) – Case report

Introduction and importance

Case presentation

Clinical discussion

Conclusion

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Symptomatic patients presenting upper urinary tract urothelial carcinoma benefit from surgery, a minimal invasive approach being preferable.

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Nephroureterectomy with lymphnode metastasis poses surgical challenges in order to achieve negative resection margins and optimal lymphadenectomy.

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A combined 3D laparoscopic and Da Vinci X robotic surgical approach offered improved operatory time and better management of intra-pelvic disease. An optimal surgical strategy respects the surgical experience of the main surgeon combined with access to minimal invasive technology. The gentle and precise movements of the Da Vinci robot allowed an accurate dissection with en bloc specimen excision and optimal lymphadenectomy, presenting possible implications in staging and oncologic outcomes.

Prognostic assessments in patients with upper tract urothelial carcinoma undergoing radical nephroureterectomy and systematic regional lymph node dissection

OBJECTIVES

Systematic regional lymph node dissection (LND) combined with radical nephroureterectomy (RNU) has been reported to improve the outcomes of upper tract urothelial carcinoma (UTUC) patients. The objective of the present study was to assess the prognostic outcomes of UTUC patients undergoing systematic regional LND combined with RNU.

PATIENTS AND METHODS

We conducted a retrospective evaluation of prognostic outcomes of 68 consecutive UTUC patients treated with RUN and systematic regional LND.

RESULTS

The median durations of recurrence-free survival (RFS) and overall survival (OS) were 45 and 166 months, respectively. Univariate analyses of several parameters showed that despite the lack of a significant predictor for RFS, the presence of lymph node metastasis correlated with poor OS.

CONCLUSION

These results suggest that comparatively favorable outcomes are achievable in UTUC patients by RNU and systematic regional LND; however, special attention is needed for patients with nodal involvement even after systematic regional LND due to the adverse impact of this factor on OS.

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.

Diagnostic and Therapeutic Challenges of Rare Urogenital Cancers: Urothelial Carcinoma of the Renal Pelvis, Ureters and Urethra

Urothelial carcinoma (UC) is a neoplastic growth that affects the lining of the urinary tract from the renal pelvis to the distal urethra. Urothelial cancer occurs less commonly along the upper urinary tract (renal pelvis and ureter) accounting for 5-10% and even rarer along the urethra approximately less than 1%. The incidence of UC of the upper urinary tract and urethra has been reported in the United States and Europe by the Surveillance, Epidemiology, and End Results Program and the Rare Cancers in Europe project, respectively. Considering the rarity of upper tract urothelial carcinoma (UTUC) and primary urethral cancer (PUC), there is a paucity of data from Sub-Saharan Africa. Both the European Association of Urology guideline and the National Comprehensive Cancer Network guideline have provided some clinical updates on the management of UTUC and PUC. However, UTUC and PUC present mostly at a more advanced stage than UC of bladder. A high index of suspicion is necessary for diagnosis even more for UTUC. Organ-sparing surgery is possible for both localized UTUC and PUC but stringent follow-up with urine cytology, endoscopy and imaging is mandated for early detection of recurrence.

Optimal Management of Upper Tract Urothelial Carcinoma: Current Perspectives

INTRODUCTION

Upper tract urothelial carcinoma (UTUC) is a relatively uncommon urologic malignancy for which there has not been significant improvement in survival over the past few decades, highlighting the need for optimal multi-modality management.

METHODS

A non-systematic review of the latest literature was performed to include relevant articles up to June 2019. It summarizes the epidemiologic risk factors associated with UTUC, including smoking, carcinogenic aromatic amines, arsenic, aristolochic acid, and Lynch syndrome. Molecular pathways underlying UTUC and potential druggable targets are outlined.

RESULTS

Surgical management for UTUC includes kidney-sparing surgery (KSS) for low-risk disease and radical nephroureterectomy (RNU) for high-risk disease. Endoscopic management of UTUC may include ureteroscopic or percutaneous resection. Topical instillation therapy post-KSS aims to reduce recurrence, progression and to treat carcinoma-in-situ; this may be achieved retrogradely (via ureteric catheterization), antegradely (via percutaneous nephrostomy) or via reflux through double-J stent. RNU, which may be performed via open, laparoscopic or robot-assisted approaches, is the gold standard treatment for high-risk UTUC. The distal cuff may be dealt with extravesical, transvesical or endoscopic techniques. Peri-operative chemotherapy and immunotherapy are increasingly utilized; level 1 evidence exists for adjuvant chemotherapy, but neoadjuvant chemotherapy is favored as kidney function is better prior to RNU. Immunotherapy is primarily reserved for metastatic UTUC but is currently being investigated in the perioperative setting.

CONCLUSION

The optimal management of UTUC includes a firm understanding of the epidemiological factors and molecular pathways. Surgical management includes KSS for low-risk disease and RNU for high-risk disease. Peri-operative immunotherapy and chemotherapy may be considered as evidence mounts.

Adverse Effect of Lymph Node Dissection in Metastatic Renal Cell Cancer Patients Treated with Cytoreductive Nephrectomy: A Contemporary Analysis of Survival

Background and objectives: In patients with metastatic renal cell cancer (mRCC), cytoreductive nephrectomy (CN) may occasionally be performed. However, the role of lymph node dissection (LND) for such cases is unknown in era of target therapy. To test the effect of LND at CN on cancer-specific survival (CSS), overall survival (OS) in era of target therapy compared with no LND in patients with mRCC.

Methods: A total of 4690 mRCC patients treated with CN were identified within the Surveillance, Epidemiology, and End Result (SEER) database (2006-2015). Survival differences were assessed by Kaplan-Meier estimate and compared using log-rank test. Multivariable Cox regression analysis (MCR) was used to evaluate the effect of LND on CSS and OS.

Results: Within the SEER database, 1902 (40.6%) of 4690 mRCC patients underwent LND at CN. MCR analysis showed that LND at CN exhibited lower CSS (hazard ratio [HR] 1.18, 95% confidence interval (CI) 1.09-1.27; p < 0.01) and OS (HR 1.13, 95% CI 1.05-1.21; p < 0.01) compared with non-LND in mRCC patients. The adverse effect of LND on CSS and OS were also detected in metastatic patients with clear cell RCC (ccRCC) and non-ccRCC (all p<0.0001). Additionally, the association of number of resected node with CSS (HR 0.98, 95% CI 0.88-1.10; p = 0.68) and OS (HR 1.00, 95% CI 0.89-1.11; p = 0.93) were not observed in MCR analysis.

Conclusion: We are the first to demonstrate that LND at CN is associated with poor CSS and OS in metastatic patients with ccRCC and non-ccRCC. Considering that the current study is retrospective, these findings' impact on clinical practice needs to be further verified in future validation studies.

Robotic radical nephroureterectomy and segmental ureterectomy for upper tract urothelial carcinoma: a multi-institutional experience

PURPOSE

To report a multi-institutional experience on robotic radical nephroureterectomy (RNU) and segmental ureterectomy (SU) for upper tract urothelial carcinoma (UTUC).

METHODS

Data were prospectively collected from patients with non-metastatic UTUC undergoing robotic SU or RNU at three referral centers between 2015 and 2018. Transperitoneal, single-docking robotic RNU followed established principles. Bladder cuff excision (BCE) was performed with robotic or open approach. Techniques for SU included: ureteral resection and primary uretero-ureterostomy; partial pyelectomy and modified pyeloplasty; ureteral resection with BCE and direct- or psoas hitch-ureteroneocystostomy. We retrospectively evaluated the technical feasibility, and peri-operative and oncologic outcomes after robotic RNU/SU.

RESULTS

81 patients were included. No case required conversion to open surgery. Early major (Clavien-Dindo grade > 2) complications were reported in six (7.4%) patients (two after SU, four after RNU). Three patients experienced late major complications (one after SU, two after RNU). Median ΔeGFR at 3 months was - 1 ml/min/1.73 m² after SU and - 15 ml/min/1.73 m² after RNU. Positive surgical margins were recorded in five patients (one after SU, four after RNU). Median follow-up was 21 months and 22 months in the SU and RNU groups, respectively. Three (20%) patients had ipsilateral upper tract recurrence after SU, while five (7.5%) developed metastases after RNU. No case of port-site metastases or peritoneal carcinomatosis was reported. At last follow-up, 67 (82.7%) patients were alive without evidence of disease.

CONCLUSION

Robotic SU and RNU are technically feasible and achieved promising peri-operative and oncologic outcomes in selected patients with non-metastatic UTUC.

Templates of Lymph Node Dissection for Renal Cell Carcinoma: A Systematic Review of the Literature

Background: The role of lymph node dissection (LND) for renal cell carcinoma (RCC) is controversial. Notably, the conflicting evidence on the benefits and harms of LND is inherently linked to the lack of consensus on both anatomic templates and extent of lymphadenectomy. Herein, we provide a detailed overview of the most commonly dissected templates of LND for RCC, focusing on key anatomic landmarks and patterns of lymphatic drainage.

Methods: A systematic review of the English-language literature was performed without time filters in July 2018 in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement recommendations. The primary endpoint was to summarize the most commonly dissected templates of LND according to the side of RCC.

Results: Overall, 25 studies were selected for qualitative analysis. Of these, most were retrospective. The LND template was heterogeneous across studies. Indications and extent of LND were either not reported or not standardized in most series. The most commonly dissected template for right-sided tumors included hilar, paracaval, and precaval nodes, with few authors extending the dissection to the inter-aortocaval, retrocaval, common iliac or pre/paraaortic nodes. Similarly, the most commonly dissected template for left-sided tumors encompassed the renal hilar, preaortic and paraaortic nodes, with few authors reporting a systematic dissection of inter-aortocaval, retro-aortic, common iliac, or para-caval nodes.

Conclusions: In light of the unpredictable renal lymphatic anatomy and the evidence from available prospective mapping studies, the extent of the most commonly dissected templates might be insufficient to catch the overall anatomic pattern of lymphatic drainage from RCC.

Radiomics-guided therapy for bladder cancer: Using an optimal biomarker approach to determine extent of bladder cancer invasion from t2-weighted magnetic resonance images

Background

Current clinical staging methods are unable to accurately define the extent of invasion of localized bladder cancer, which affects the proper use of systemic therapy, surgery, and radiation. Our purpose was to test a novel radiomics approach to identify optimal imaging biomarkers from T2-weighted magnetic resonance imaging (MRI) scans that accurately classify localized bladder cancer into 2 tumor stage groups (≤T2 vs >T2) at both the patient level and within bladder subsectors.

Method and Materials

Preoperative T2-weighted MRI scans of 65 consecutive patients followed by radical cystectomy were identified. A 3-layer, shell-like volume of interest (VOI) was defined on each MRI slice: Inner (lumen), middle (bladder wall), and outer (perivesical tissue). An optimal biomarker method was used to identify features from 15,834 intensity and texture properties that maximized the classification of patients into ≤T2 versus >T2 groups. A leave-one-out strategy was used to cross-validate the performance of the identified biomarker feature set at the patient level. The performance of the feature set was then evaluated at the subsector level of the bladder by dividing the VOIs into 8 radial sectors.

Results

A total of 9 optimal biomarker features were derived and demonstrated a sensitivity, specificity, accuracy of prediction, and area under a receiver operating characteristic curve of 0.742, 0.824, 0.785, and 0.806, respectively, at the patient level and 0.681, 0.788, 0.763, and 0.813, respectively, at the radial sector level. All 9 selected features were extracted from the middle shell of the VOI and based on texture properties.

Conclusions

An approach to select a small, highly independent feature set that is derived from T2-weighted MRI scans that separate patients with bladder cancer into ≤T2 versus >T2 groups at both the patient level and within subsectors of the bladder has been developed and tested. With external validation, this radiomics approach could improve the clinical staging of bladder cancer and optimize therapeutic management.