The Impact of Diagnostic Ureteroscopy Prior to Radical Nephroureterectomy on Oncological Outcomes in Patients with Upper Tract Urothelial Carcinoma: A Comprehensive Systematic Review and Meta-Analysis

Decisional and prognostic impact of diagnostic ureteroscopy in high-risk upper tract urothelial carcinoma: A multi-institutional collaborative analysis (ROBUUST collaborative group)

BACKGROUND

Diagnostic ureteroscopy (URS) with or without biopsy remains a subject of contention in the management of upper tract urothelial carcinoma (UTUC), with varying recommendations across different guidelines. The study aims to analyse the decision-making and prognostic role of diagnostic ureteroscopy (URS) in high-risk UTUC patients undergoing curative surgery.

MATERIALS AND METHODS

In this retrospective multi-institutional analysis of high-risk UTUC patients from the ROBUUST dataset, a comparison between patients who received or not preoperative URS and biopsy before curative surgery was carried out. Logistic regression analysis evaluated differences between patients receiving URS and its impact on treatment strategy. Survival analysis included 5-year recurrence-free survival (RFS), metastasis-free survival (MFS), cancer-specific survival (CSS) and overall survival (OS). After adjusting for high-risk prognostic group features, Cox proportional hazard model estimated significant predictors of time-to-event outcomes.

RESULTS

Overall, 1,912 patients were included, 1,035 with preoperative URS and biopsy and 877 without. Median follow-up: 24 months. Robot-assisted radical nephroureterectomy was the most common procedure (55.1%), in both subgroups. The 5-year OS (P = 0.04) and CSS (P < 0.001) were significantly higher for patients undergoing URS. The 5-year RFS (P = 0.6), and MFS (P = 0.3) were comparable between the 2 groups. Preoperative URS and biopsy were neither a significant predictor of worse oncological outcomes nor of a specific treatment modality.

CONCLUSIONS

The advantage in terms of OS and CSS in patients undergoing preoperative URS could derive from a better selection of candidates for curative treatment. The treatment strategy is likely more influenced by tumor features than by URS findings.

Single Early Intravesical Instillation of Epirubicin for Preventing Bladder Recurrence after Nephroureterectomy in Upper Urinary Tract Urothelial Carcinoma

PURPOSE

We aimed to assess the effectiveness of early single intravesical administration of epirubicin in preventing intravesical recurrence after radical nephroureterectomy for upper tract urothelial carcinoma.

MATERIALS AND METHODS

Patients with upper tract urothelial carcinoma who underwent radical nephroureterectomy between November 2018 and May 2022 were retrospectively reviewed. Intravesical epirubicin was administered within 48 hours if no evidence of leakage was observed. Epirubicin (50 mg) in 50 mL normal saline solution was introduced into the bladder via a catheter and maintained for 60 minutes. The severity of adverse events was graded using the Clavien-Dindo classification. We compared intravesical recurrence rate between the two groups. Multivariate analyses were performed to identify the independent predictors of bladder recurrence following radical nephroureterectomy.

RESULTS

Epirubicin (n=55) and control (n=116) groups were included in the analysis. No grade 1 or higher bladder symptoms have been reported. A statistically significant difference in the intravesical recurrence rate was observed between the two groups (11.8% at 1 year in the epirubicin group vs. 28.4% at 1 year in the control group; log-rank p=0.039). In multivariate analysis, epirubicin instillation (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.20 to 0.93; p=0.033) and adjuvant chemotherapy (HR, 0.29; 95% CI, 0.13 to 0.65; p=0.003) were independently predictive of a reduced incidence of bladder recurrence.

CONCLUSION

This retrospective review revealed that a single immediate intravesical instillation of epirubicin is safe and can reduce the incidence of intravesical recurrence after radical nephroureterectomy. However, further prospective trials are required to confirm these findings.

Violation of onco-surgical principles is associated with survival outcomes in upper tract urothelial carcinomas after radical nephroureterectomy

OBJECTIVE

Disease recurrence, particularly intravesical recurrence (IVR) after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC), is common. We investigated whether violations of onco-surgical principles before or during RNU, collectively referred to as surgical violation (SV), were associated with survival outcomes.  Material and methods: Data from a consecutive series of patients who underwent RNU for UTUC 2001-2012 at Skåne University Hospital Lund/Malmö were collected. Preoperative insertion of a nephrostomy tube, opening the urinary tract during surgery or refraining from excising the distal ureter were considered as SVs. Survival outcomes in patients with and without SV (IVR-free [IVRFS], disease-specific [DSS] and overall survival [OS]) were assessed using multivariate Cox regression analyses (adjusted for tumour stage group, prior or concomitant bladder cancer, comorbidity and preoperative urinary cytology).

RESULTS

Of 150 patients, 47 (31%) were subjected to at least one SV. Overall, SV was not associated with IVRFS (HR 0.81, 95% CI 0.4-1.6) but with worse DSS (HR 1.9, 95% CI 1.03-3.7) and OS (HR 1.9, 95% CI 1.2-3) in multivariable analysis. Additional analyses with a broader definition of SV including also preoperative instrumentation of the upper urinary tract (ureteroscopy and/or double J stenting) showed similar outcomes for DSS (HR 2.1, 95% CI 1.1-4.3).

CONCLUSION

Worse survival outcomes, despite no difference in IVR, for patients that were subjected to the violation of sound onco-surgical principles before or during RNU for UTUC strengthen the notion that adhering to such principles is a cornerstone in upper tract urothelial cancer surgery.

Development and validation of a clinical and ultrasound features-based nomogram for preoperative differentiation of renal urothelial carcinoma and central renal cell carcinoma

PURPOSE

This study aimed to develop and validate an ultrasound (US)-based nomogram for the preoperative differentiation of renal urothelial carcinoma (rUC) from central renal cell carcinoma (c-RCC).

METHODS

Clinical data and US images of 655 patients with 655 histologically confirmed malignant renal tumors (521 c-RCCs and 134 rUCs) were collected and divided into training (n = 455) and validation (n = 200) cohorts according to examination dates. Conventional US and contrast-enhanced US (CEUS) tumor features were analyzed to determine those that could discriminate rUC from c-RCC. Least absolute shrinkage and selection operator regression was applied to screen clinical and US features for the differentiation of rUC from c-RCC. Using multivariate logistic regression analysis, a diagnostic model of rUC was constructed and visualized as a nomogram. The diagnostic model's performance was assessed in the training and validation cohorts by calculating the area under the receiver operating characteristic curve (AUC) and calibration plot. Decision curve analysis (DCA) was used to assess the clinical usefulness of the US-based nomogram.

RESULTS

Seven features of both clinical features and ultrasound imaging were selected to build the diagnostic model. The nomogram achieved favorable discrimination in the training (AUC = 0.996, 95% CI: 0.993-0.999) and validation (AUC = 0.995, 95% CI: 0.974, 1.000) cohorts, and good calibration (Brier scores: 0.019 and 0.016, respectively). DCA demonstrated the clinical usefulness of the US-based nomogram.

CONCLUSION

A noninvasive clinical and US-based nomogram combining conventional US and CEUS features possesses good predictive value for differentiating rUC from c-RCC.

The clinical impact of ureteroscopy for upper tract urothelial carcinoma: A multicenter study

BACKGROUND

With the development of kidney-sparing surgery and neoadjuvant chemotherapy, ureteroscopic biopsy (URSBx) has become important for the management of upper tract urothelial carcinoma (UTUC).

METHODS

We retrospectively analyzed data from 744 patients with UTUC who underwent radical nephroureterectomy (RNU), stratified into no ureteroscopy (URS), URS alone, and URSBx groups. Intravesical recurrence-free survival (IVRFS) was examined using the Kaplan-Meier method. We conducted Cox regression analyses to identify risk factors for IVR. We investigated differences between clinical and pathological staging to assess the ability to predict the pathological tumor stage and grade of RNU specimens.

RESULTS

Kaplan-Meier curves and multivariate Cox regression revealed significantly more IVR and inferior IVRFS in patients who underwent URS and URSBx. Superficial, but not invasive, bladder cancer recurrence was more frequent in the URS and URSBx groups than in the no URS group. Clinical and pathological staging agreed for 55 (32.4%) patients. Downstaging occurred for 48 (28.2%) patients and clinical understaging occurred for 67 (39.4%) patients. Upstaging to muscle-invasive disease occurred for 39 (35.8%) of 109 patients with ≤cT1 disease. Clinical and pathological grading were similar for 72 (42.3%) patients. Downgrading occurred for 5 (2.9%) patients, and clinical undergrading occurred for 93 (54.7%) patients.

CONCLUSION

URS and URSBx instrumentation will be risk factors for superficial, but not invasive, bladder cancer recurrence. Clinical understaging/undergrading and upstaging to muscle-invasive disease occurred for a large proportion of patients with UTUC who underwent RNU. These data emphasize the challenges involved in accurate UTUC staging and grading.

Summary of the Clinical Practice Guidelines for Upper Tract Urothelial Carcinoma 2023 by the Japanese Urological Association

This article is an English translation of the Clinical Practice Guidelines for Upper Tract Urothelial Carcinoma (2nd edition) published in June 2023. The Japanese Urological Association's (JUA) Guidelines Committee on Upper Tract Urothelial Carcinoma (UTUC) created a 2023 update guideline to support clinicians' current evidence-based management of UTUC and to incorporate its recommendations into clinical practice. The new guideline adhered as closely as possible to the Minds Manual for Guideline Development 2020 ver. 3.0. Findings related to epidemiological, pathological, diagnosis, treatment, and follow-up were reviewed. In addition, seven clinical questions (CQs) were set to determine the grade of recommendation and level of evidence. Preconceptions and biases were removed from the preparation process, the overall evidence was evaluated appropriately, and recommendations were made after fully considering the balance between benefits and harms. Although the evidence is still insufficient to be taken up as a CQ, the latest important information is described in seven columns, and clinical issues that should be resolved in the future related to the CQ are described as recommendations for tomorrow. We hope that these guidelines will help medical professionals, patients, and their families involved in the treatment of UTUC in their decision-making, and hope that a critical review of these guidelines will lead to further refinements in the next edition.

Consultation on UTUC II Stockholm 2022: diagnostic and prognostic methods-what's around the corner?

PURPOSE

To map current literature and provide an overview of upcoming future diagnostic and prognostic methods for upper tract urothelial carcinoma (UTUC), including translational medical science.

METHODS

A scoping review approach was applied to search the literature. Based on the published literature, and the experts own experience and opinions consensus was reached through discussions at the meeting Consultation on UTUC II in Stockholm, September 2022.

RESULTS

The gene mutational profile of UTUC correlates with stage, grade, prognosis, and response to different therapeutic strategies. Analysis of pathway proteins downstream of known pathogenic mutations might be an alternative approach. Liquid biopsies of cell-free DNA may detect UTUC with a higher sensitivity and specificity than urinary cytology. Extracellular vesicles from tumour cells can be detected in urine and may be used to identify the location of the urothelial carcinoma in the urinary tract. 3D microscopy of UTUC samples may add information in the analysis of tumour stage. Chemokines and chemokine receptors were linked to overall survival and responsiveness to neoadjuvant chemotherapy in muscle-invasive bladder cancer, which is potentially also of interest in UTUC.

CONCLUSION

Current diagnostic methods for UTUC have shortcomings, especially concerning prognostication, which is important for personalized treatment decisions. There are several upcoming methods that may be of interest for UTUC. Most have been studied for urothelial carcinoma of the bladder, and it is important to keep in mind that UTUC is a different entity and not all methods are adaptable or applicable to UTUC.

Consultation on UTUC II Stockholm 2022: diagnostics, prognostication, and follow-up-where are we today?

PURPOSE

To summarise the current knowledge regarding diagnostics, prognostication and follow-up in upper tract urothelial carcinoma (UTUC).

METHODS

A scoping review combined with expert opinion was applied to provide an overview of the current research field. Based on the published literature and the experts' own experience and opinions, consensus was reached through presentations and discussions at the meeting Consultation on UTUC II in Stockholm 2022.

RESULTS

The strongest prognostic factors in UTUC are tumour grade and stage. They are correlated, and grade is used for indirect staging. The diagnostic examinations should include multiphase computed tomography urography (CTU) with corticomedullary phase, and urethrocystoscopy with cytology. If there is no clear diagnosis for clinical decision-making, ureterorenoscopy (URS) with focal cytology and biopsies should be performed. Both WHO classification systems (1973/1999 and 2004/2016) should be used. Novel biomarker tests are not yet widespread nor recommended for the detection of UTUC. Long-term, regular follow-up, including URS in patients who have had organ-sparing treatment, is important to check for tumour recurrences, intravesical recurrences, metastases and progression of the tumour.

CONCLUSION

Proper diagnostics with correct grading of UTUC are necessary for appropriate treatment decisions. The diagnostics should include CTU with corticomedullary phase, urine or bladder cytology, URS with focal barbotage cytology, and biopsies when needed for proper diagnosis and risk stratification. Regular, long-term follow-ups are fundamental, due to the high rate of recurrence and risk of progression.

Effects of different combinations of radical nephroureterectomy and bladder cuff excision procedures for upper tract urothelial carcinoma on bladder recurrence

PURPOSE

To compare the effects of different combinations of radical nephroureterectomy (RNU) and bladder cuff excision (BCE) surgical procedures on intravesical recurrence (IVR) in patients with upper tract urothelial carcinoma (UTUC).

MATERIALS AND METHODS

This retrospective observational study included 452 patients who underwent RNU with BCE for UTUC between January 2010 and December 2020. The patients were classified into three groups based on different combinations of RNU and BCE surgical procedures: open RNU with open BCE (group 1, n=104), minimally invasive (MIS) RNU with open BCE (group 2, n=196), and MIS RNU with intracorporeal BCE (group 3, n=152). Data on demographics, body mass index, history, preoperative renal function, perioperative status, tumor characteristics, histopathology, and recurrence conditions were collected. Multivariate Cox regression analyses were performed to determine the impact of the surgical procedures on IVR. P-values < 0.05 were considered statistically significant.

RESULTS

After a median follow-up of 29.5 months, the IVR rate was 29.6% and the IVR-free survival rate was the lowest in group 2 (group 1 vs. group 2 vs. group 3: 69.0% vs. 55.1% vs. 67.5%; log-rank P=0.048). The overall survival rate was comparable among the three groups. Multivariate analysis revealed that group 2 had a significantly higher risk of IVR than group 1 (hazard ratio=1.949, 95% confidence interval=1.082-3.511, P=0.026), while groups 1 and 3 had similar risks.

CONCLUSIONS

For patients with UTUC, MIS RNU with open BCE is associated with a higher risk of IVR than open RNU with open BCE and MIS RNU with intracorporeal BCE.

Current methods facilitating diagnosis of upper tract urothelial carcinoma: a comprehensive literature review

PURPOSE OF REVIEW

Currently, kidney-sparing surgeries are considered the preferred approach in low-risk tumours and in selected high-risk patients. Therefore, accurate diagnosis of UTUC is crucial for further management. The purpose of this review is to summarize available methods facilitating the diagnosis of upper tract urothelial carcinoma (UTUC).

RECENT FINDINGS

Recent articles propose numerous techniques of UTUC diagnosis. In this review, imaging, as well as, urine-based and endoscopic methods have been described and assessed.

SUMMARY

Regarding imaging, computed tomography urography remains a gold standard, while PET is superior in search for small lesions and nodal metastases. However, contrast-enhanced ultrasonography also shows promise. On the contrary, available urine tests, such as urinary cytology, fluorescent in-situ hybridization, Xpert, DNA methylation analysis, urine-based liquid biopsy, p16/Ki-67 dual immunolabelling, ImmunoCyt and NMP22 are either poorly researched, or not accurate enough to use solely. Finally, during ureterorenoscopy, photodynamic diagnosis and narrow-band imaging can facilitate proper visualization of the tumor. Endoluminal ultrasonography and confocal laser endomicroscopy can potentially improve staging and grading of UTUC. Also, the 'form tackle' biopsy should be performed using a basket in papillary lesions and cold-cup biopsy of flat or sessile lesions. Even though cryobiopsy shows promise in UTUC diagnosis, in-vivo studies are necessary before it is introduced into clinical practice.

A 6-month maintenance schedule of mitomycin C after radical nephroureterectomy for upper tract urothelial carcinoma for the prevention of intravesical recurrence: a retrospective, single center study

PURPOSE

To show the effect of a 6-month (4 times weekly followed by 5 times monthly) maintenance mitomycin C regimen on the prevention of intravesical recurrence (IVR) after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC).

METHODS

A total of 119 patients undergoing a RNU between 2007 and 2021 in a single center hospital were retrospectively reviewed. A total of 66 patients were eligible for further analysis. 27 patients received no post-operative MMC (median follow-up: 110 months) and 39 patients received a 6-month (4 times weekly, 5 times monthly) maintenance regimen of MMC (median follow up: 48 months). The primary outcome was the 1-, 2- and 5-year bladder recurrence free survival (BRFS).

RESULTS

There was a significant difference (p = 0.001) in BRFS between the two groups. The 1-, 2, and 5-year BRFS for the MMC- group was 67%, 63% and 43%, respectively. The 1-, 2- and 5-year BRFS for the MMC + group was 95%, 86% and 86%, respectively. Univariate analysis showed no other potential prognostic factors that had a significant effect on the BRFS.

CONCLUSION

A 6-month maintenance schedule of MMC is effective at significantly reducing the risk of IVR after RNU for UTUC. We could not find any other significant prognostic factors to predict IVR.

Preoperative upper tract invasive diagnostic modalities are associated with intravesical recurrence following surgery for upper tract urothelial carcinoma: A population-based study

BACKGROUND

Intravesical recurrence (IVR) after surgery for upper tract urothelial carcinoma (UTUC) is a clinical problem. We investigated if preoperative invasive diagnostic modalities (IDM) such as antegrade/retrograde uretero-pyelography and/or selective urine cytology/barbotage, and URS with or without concomitant biopsy are associated with IVR after radical surgery for UTUC. Risk of death from urothelial cancer and all causes was investigated as secondary outcomes.

METHODS

We investigated a population-based cohort of 1038 consecutive patients subjected to radical surgery for UTUC 2015-2019 in Sweden, using the Bladder Cancer Data Base Sweden (BladderBaSe 2.0), comprising all patients in the Swedish National Registry of Urinary Bladder Cancer. Risk estimates of IVR, death from urothelial cancer, and all causes was assessed using multivariable Cox regression models.

RESULTS

The study included 536 cases with and 502 without preoperative IDM. IDM was associated with increased risk of IVR (HR 1.24, 95% CI 1.03-1.52) and risk of urothelial cancer death (HR 1.56, CI 1.12-2.18), compared to no IDM after a median follow-up of 1.3 yrs. Stratified analysis for tumor location showed that IDM was associated with risk of IVR in ureteric cancer (HR 1.66, 95% CI 1.21-2.28) but not in renal pelvic cancer (HR 1.07, 95% CI 0.81-1.41). Limitations included the observational setting and the lack of variables such as tumour grade, multifocality and preoperative hydronephrosis.

CONCLUSIONS

Worse outcomes for patients subjected to preoperative IDM highlight the need for carefully considering diagnostic decisions for UTUC patients, specifically in tumours located in the ureter.

Bladder Recurrence Following Upper Tract Surgery for Urothelial Carcinoma: A Contemporary Review of Risk Factors and Management Strategies

Context

Bladder recurrences have been reported in 22-47% of patients after surgery for upper urinary tract urothelial carcinoma (UTUC). This collaborative review focuses on risk factors for and treatment strategies to reduce bladder recurrences after upper tract surgery for UTUC.

Objective

To review the current evidence on risk factors and treatment strategies for intravesical recurrence (IVR) after upper tract surgery for UTUC.

Evidence acquisition

This collaborative review is based on a literature search of PubMed/Medline, Embase, Cochrane Library, and currently available guidelines on UTUC. Relevant papers on bladder recurrence (etiology, risk factors, and management) after upper tract surgery were selected. Special attention has been paid to (1) the genetic background of bladder recurrences, (2) bladder recurrences after ureterorenoscopy (URS) with or without a biopsy, and (3) postoperative or adjuvant intravesical instillations. The literature search was performed in September 2022.

Evidence synthesis

Recent evidence supports the hypothesis that bladder recurrences after upper tract surgery for UTUC are often clonally related. Clinicopathologic risk factors (patient, tumor, and treatment related) have been identified for bladder recurrences after UTUC diagnosis. Specifically, the use of diagnostic ureteroscopy before radical nephroureterectomy (RNU) is associated with an increased risk of bladder recurrences. Further, a recent retrospective study suggests that performing a biopsy during ureteroscopy may further worsen IVR (no URS: 15.0%; URS without biopsy: 18.4%; URS with biopsy: 21.9%). Meanwhile, a single postoperative instillation of intravesical chemotherapy has been shown to be associated with a reduced bladder recurrence risk after RNU compared with no instillation (hazard ratio 0.51, 95% confidence interval 0.32-0.82). Currently, there are no data on the value of a single postoperative intravesical instillation after ureteroscopy.

Conclusions

Although based on limited retrospective data, performing URS seems to be associated with a higher risk of bladder recurrences. Future studies are warranted to assess the influence of other surgical factors as well as the role of URS biopsy or immediate postoperative intravesical chemotherapy after URS for UTUC.

Patient summary

In this paper, we review recent findings on bladder recurrences after upper tract surgery for upper urinary tract urothelial carcinoma.

Intravesical Recurrence after Radical Nephroureterectomy in Patients with Upper Tract Urothelial Carcinoma Is Associated with Flexible Diagnostic Ureteroscopy, but Not with Rigid Diagnostic Ureteroscopy

(1) Background: We assessed the impact of diagnostic ureteroscopy (URS) on intravesical recurrence (IVR) following radical nephroureterectomy (RNU) for upper tract urothelial carcinoma according to the type of URS. (2) Methods: Data on 491 consecutive patients who underwent RNU at two institutions between 2016 and 2019 were retrospectively reviewed. The study population was classified according to the type of URS performed before RNU as follows: non-URS, rigid URS, and flexible URS. The study outcome was IVR occurring within 1 year of RNU. Univariable and multivariable Cox proportional hazards models were used to estimate the risk of IVR. (3) Results: Altogether, 396 patients were included for analysis. Rigid and flexible URS were performed in 178 (45%) and 111 (28%) patients, respectively, while 107 (27%) patients did not undergo URS. IVR was identified in 99 (25%) patients. Multivariable Cox regression analysis revealed that the flexible URS group was significantly associated with increased IVR, compared to the non-URS group (HR = 1.807, p = 0.0416). No significant difference in IVR was observed between the non-URS and rigid URS groups (HR = 1.301, p = 0.3388). (4) Conclusions: In patients with UTUC undergoing RNU, rigid URS may not increase the risk of IVR, whereas flexible URS appears to be associated with a higher risk of IVR.

Adverse Prognostic Impact of Diagnostic Ureterorenoscopy in a Subset of Patients with High-Risk Upper Tract Urothelial Carcinoma Treated with Radical Nephroureterectomy

Background: We hypothesized that diagnostic ureterorenoscopy (URS) may adversely affect prognosis in a subset of patients with high-risk upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU). Methods: The present retrospective study included 143 patients with UTUC treated between 2010 and 2021 at two tertiary care hospitals, of whom 79 received URS prior to RNU. Subgroups were stratified by clinicopathological variables relevant to prognosis. The primary endpoint was to evaluate the prognostic impact of URS on overall survival (OS) and progression-free survival (PFS) after RNU. Results: During follow-up (median 54 months for survivors), 32 cases of all-cause mortality and 40 cases of progression were recorded. No significant difference was found in OS or PFS between patients with and without URS. Subgroup analysis demonstrated that URS was significantly associated with worse OS (p < 0.001) and PFS (p = 0.008) in 29 patients with non-papillary and ≥pT3 UTUC. Importantly, URS did not have any adverse effects on prognosis in 62 patients with papillary and ≤pT2 UTUC (p = 0.005). Conclusions: URS may adversely affect prognosis of UTUC patients, specifically non-papillary and ≥pT3 disease. URS may better be avoided in patients with high-risk UTUC features unless URS is necessary to diagnose UTUC. This study also corroborates the oncological safety of URS in those with low-risk UTUC.

The Impact of Surgical Waiting Time on Oncological Outcomes in Patients with Upper Tract Urothelial Carcinoma Undergoing Radical Nephroureterectomy: A Systematic Review

Radical nephroureterectomy (RNU) with bladder cuff excision is a standard of care in patients with high-risk upper tract urothelial carcinoma (UTUC). Although several recommendations and guidelines on the delayed treatment of urologic cancers exist, the evidence on UTUC is scarce and ambiguous. The present systematic review aimed to summarize the available evidence on the survival outcomes after deferred RNU in patients with UTUC. A systematic literature search of the three electronic databases (PubMed, Embase, and Cochrane Library) was conducted until 30 April 2022. Studies were found eligible if they reported the oncological outcomes of patients treated with deferred RNU compared to the control group, including those patients treated with RNU without delay. Primary endpoints were cancer-specific survival (CSS), overall survival (OS), and recurrence-free survival (RFS). In total, we identified seven eligible studies enrolling 5639 patients. Significant heterogeneity in the definition of “deferred RNU” was found across the included studies. Three out of five studies reporting CSS showed that deferring RNU was associated with worse CSS. Furthermore, three out of four studies reporting OS found a negative impact of delay in RNU on OS. One out of three studies reporting RFS found a negative influence of delayed RNU on RFS. While most studies reported a 3 month interval as a significant threshold for RNU delay, some subgroup analyses showed that a safe delay for RNU was less than 1 month in patients with ureteral tumors (UT) or less than 2 months in patients with hydronephrosis. In conclusion, long surgical waiting time for RNU (especially more than 3 months after UTUC diagnosis) could be considered as an important risk factor having a negative impact on oncological outcomes in patients with UTUC; however, the results of the particular studies are still inconsistent. The safe delay for RNU might be shorter in specific subsets of high-risk patients, such as those with UT and/or hydronephrosis at the time of diagnosis. High-quality additional studies are required to establish evidence for valid recommendations.

Improving the Quality of Human Upper Urinary Tract Specimens by Cryobiopsy

Objective

The quality of histopathological specimens obtained from the upper urinary tract with conventional flexible ureterorenoscopic biopsy needs to be improved. We investigated the feasibility and biopsy quality of specimens obtained by cryobiopsy, compared with standard ureterorenoscopic biopsy techniques in a human ex vivo model.

Materials and Methods

Human ureters obtained from nephrectomy specimens (N=12) were dissected and canulated with an ureteral access sheath. Ureterorenoscopic biopsies were randomly obtained from different sites of the renal pelvic caliceal system using different types of instruments. The performance of two newly developed flexible cryoprobes with outer diameters of 1.1 mm (CB11) and 0.9 mm (CB09) was compared with that of the biopsy forceps(FB) and Bigopsy®(BiG) and two different Dormia baskets N‐Gage (NG) and Zero‐Tip (ZT). We assessed the feasibility of the various biopsy techniques based on the number of biopsy attempts needed to obtain macroscopically discernible biopsies. The specimens were examined histopathologically for size, biopsy quality, presence of various artifact types, and representativeness.

Results

Biopsies taken with the cryoprobes showed a higher biopsy quality than biopsies taken with the comparative instruments. The CB11 provided significantly larger biopsies than forceps biopsies and also than biopsies with ZT. The CB09 was able to collect larger samples when compared with the FB and BiG biopsy forceps. There were no significant differences in artifact area, except for the CB11 cryoprobe compared with the NG. To clarify the results a subdivision of larger or smaller than 20% artifact area was performed. A significant difference was found between CB11 and the forceps biopsies, as well as between CB11 and NG and ZT in favor of the cryoprobe. The representation of the histopathological sample was also determined. Biopsies taken with CB11 were more representative compared with forceps biopsies BiG and FB and basket biopsies NG and ZT.

Conclusions

In a standardized comparative ex vivo setting, larger biopsies were obtained by using the cryobiopsy technique with the CB11 probe. Qualitatively, cryobiopsy specimens were overlaid by fewer artifacts and a higher biopsy quality was achieved in histopathologic examination compared with standard instrumentation. Further stepwise development will transfer the promising cryobiopsy technique into the clinical setting.