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.

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.

Consultation on UTUC, Stockholm 2018 aspects of diagnosis of upper tract urothelial carcinoma

Purpose

To summarize knowledge on upper urinary tract carcinoma (UTUC) regarding diagnostic procedures, risk factors and prognostic markers.

Methods

A scoping review approach was applied to search literature in Pubmed, Web of Science, and Embase. Consensus was reached through discussions at Consultation on UTUC in Stockholm, September 2018.

Results

Tumor stage and grade are the most important prognostic factors. CT urography (CTU) including corticomedullary phase is the preferred imaging modality. A clear tumor on CTU in combination with high-grade UTUC in urine cytology identifies high-risk UTUC, and in some cases indirect staging can be obtained. Bladder urine cytology has limited sensitivity, and in most cases ureterorenoscopy (URS) with in situ samples for cytology and histopathology are mandatory for exact diagnosis. Image-enhancing techniques, Image S1 and narrow-band imaging, may improve tumor detection at URS. Direct confocal laser endomicroscopy may help to define grade during URS. There is strong correlation between stage and grade, accordingly correct grading is crucial. The correlation is more pronounced using the 1999 WHO than the 2004 classification: however, the 1999 system risks greater interobserver variability. Using both systems is advisable. A number of tissue-based molecular markers have been studied. None has proven ready for use in clinical practice.

Conclusions

Correct grading and staging of UTUC are mandatory for adequate treatment decisions. Optimal diagnostic workup should include CTU with corticomedullary phase, URS with in situ cytology and biopsies. Both WHO classification systems (1999 and 2004) should be used to decrease risk of undergrading or overtreatment.

[Biopsy techniques in the upper urinary tract for the diagnosis of urothelial carcinoma: systematic review]

BACKGROUND

The diagnostic accuracy of ureteroscopic biopsies in the upper urinary tract is limited by technical difficulties during extraction and small sample size.

OBJECTIVES

To evaluate the impact of different techniques and instruments on the histopathologic quality and diagnostic yield of extracted samples as well as the predictive value of clinical grading and staging on final pathologic stage at radical nephroureterectomy.

MATERIALS AND METHODS

For this systematic review, we searched PubMed and Embase databases for original publications and meeting abstracts according to the PRISMA guidelines.

RESULTS

Overall, we included 23 studies which comprised a total of 1547 biopsies for the investigation of diagnostic yield and 778 patients for the assessment of grade and stage concordance. We found that the median diagnostic yields of big retrograde 2F [french] forceps, antegrade 3F forceps and baskets in combination with forceps were 92% (range 83-100), 72% (50-90) and 91% (78-94), respectively. Median rates of grade concordance and upgrading across all techniques ranged between 78-89% and 5-16%, respectively, without relevant differences.

CONCLUSIONS

The choice of biopsy technique affects the ability to diagnose upper tract urothelial carcinoma. The correct determination of pathologic grading is comparable between different techniques. The combination of biopsy forceps and baskets during ureterorenoscopy seems to achieve optimal diagnostic accuracy.

Cryobiopsy in the Upper Urinary Tract: Preclinical Evaluation of a Novel Device

OBJECTIVE

To develop a novel device for cryobiopsy of the upper urinary tract (UUT) and to evaluate its feasibility in a standardized preclinical setting.

MATERIALS AND METHODS

Flexible cryoprobes (diameter 0.9 mm; cooling agent CO2) were developed and used to extract biopsies in porcine UUTs. Cryosamples obtained by ureterorenoscopy were systematically compared with biopsy specimens obtained with standard of care devices in terms of physical characteristics (deflection angle and irrigation flow rates) and histologic criteria (assessability).

RESULTS

Irrigation flow rates were significantly higher with introduced BIGopsy (2.8 ± 0.1) compared with standard forceps (0.94 ± 0.06; P < .001) and cryoprobe (1.1 ± 0.1; P < .001). Angular deflection was significantly reduced by the inserted cryoprobe (130.7° ± 1.2° vs 166.9° ± 1.1° [BIGopsy] or 161.4° ± 1.9° [standard forceps]; both P < .001). Significantly larger UUT tissue samples were obtained by the cryoprobe (mean specimen area 7.5 ± 2.5 vs 4.6 ± 2.5 mm² [BIGopsy] or 1.4 ± 1.4 mm² [standard forceps]; both P < .001). No crush artifacts were observed in cryosamples. Superior histologic assessability scores were achieved in samples obtained by the cryoprobe (mean 2.8 ± 0.8) and BIGopsy (2.3 ± 1.9) when compared with standard forceps (0.4 ± 0.9; P < .001).

CONCLUSION

Cryobiopsy in the UUT is feasible and represents a viable new option to improve the diagnostic accuracy of histopathologic evaluation. Larger and more representative tissue samples can be obtained using a cryoprobe and artifacts may be avoided. Further optimization of the probe will reduce possible restrictions of ureterorenoscopy handling when the device is inserted.

Multi-institutional Evaluation of Upper Urinary Tract Biopsy Using Backloaded Cup Biopsy Forceps, a Nitinol Basket, and Standard Cup Biopsy Forceps

OBJECTIVE

To compare the performance of 3 contemporary ureteroscopic biopsy devices for the histopathologic diagnosis of upper tract urothelial carcinoma (UTUC).

METHODS

We retrospectively reviewed 145 patients who underwent 182 urothelial biopsies using 2.4F backloaded cup biopsy forceps, a nitinol basket, or 3F standard cup biopsy forceps at 3 tertiary academic centers between 2011 and 2016. Experienced genitourinary pathologists provided an assessment of each specimen without knowledge of the device used for biopsy. For patients who underwent nephroureterectomy without neoadjuvant chemotherapy within 3 months of biopsy-proven UTUC diagnosis, the biopsy grade was compared with both the grade and stage of the surgical specimen.

RESULTS

Biopsy utilization varied among the 3 institutions (P <.0001). Significant variabilities in specimen size (P = .001), the presence of intact urothelium (P = .008), and crush artifact (P = .028) were found among the biopsy devices. The quality of specimens from backloaded cup forceps was rated similarly to the nitinol basket (P >.05) and was favored over standard cup forceps specimens. Grade concordance was not affected by specimen size (P >.05), morphology (P >.1), or location (P >.5). No difference existed among the devices in the rate of acquiring a grade concordant biopsy; however, the backloaded cup forceps provided concordant biopsies that could be distinguished as low- and high-grade (P = .02).

CONCLUSION

The backloaded cup forceps and nitinol basket obtained a higher quality urothelial specimen compared with standard cup forceps. Ureteroscopic biopsy device selection did not significantly impact the accuracy of the histologic diagnosis of UTUC.

Optimizing RNA Extraction of Renal Papilla Biopsy Tissue in Kidney Stone Formers: A New Methodology for Genomic Study

INTRODUCTION

Endoscopic tools have provided versatile examination and treatment for kidney stone procedures. Despite endourologists researching urinary stone disease using endoscopes to collect tissue, this tissue collection method is limited. Endoscopically removed tissues are small in size, restricting the types of genome-based examination possible. We investigated a new method of renal papilla biopsy and RNA extraction to establish a genomic research methodology for kidney stone disease.

PATIENTS AND METHODS

We conducted a prospective multi-institutional study and collected renal papilla specimens from consecutive percutaneous nephrolithotomy and ureteroscopy (URS) cases performed for removal of upper urinary tract stones. Renal papilla tissue was extracted using ureteroscopic biopsy forceps after stone removal. RNA was extracted using two different extraction kits, and their quantity and quality were examined. Additionally, the impact of biopsy on surgical complications was compared between cases performed with and without biopsy by matched case-control analysis adjusted for age, gender, body mass index, bilaterality, and stone burden.

RESULTS

A total of 90 biopsies from 49 patients were performed, and the median duration between specimen collection and RNA extraction was 61 days. Both univariate and multivariate analyses showed BIGopsy^® forceps usage significantly increased the total yield (p = 0.004) and quality (p = 0.001 for A260/280, p = 0.004 for A260/A230) of extracted RNA. Extraction using the RNeasy Micro Kit^® also improved A260/A230, whereas reduced RNA integrity number of extracted RNA by univariate and multivariate analyses (p = 0.002 and p < 0.001, respectively). Moreover, matched case-control study demonstrated that endoscopic renal papilla biopsy caused no significant surgical complications, including bleeding, decreased stone clearance and hematocrit, and renal dysfunction. Biopsies during URS imparted an average of 20 minutes of procedure time over nonbiopsy cases.

CONCLUSIONS

We demonstrate a safe methodology for optimal RNA extraction of renal papilla tissue. This technique will accelerate advanced genomic studies for kidney stone formers by facilitating larger tissue yields.

A Novel Technique to Improve the Processing of Minute Ureteroscopic Biopsies

To examine the ability of a new specimen handling technique to improve histopathological yield of ureteroscopic biopsies, performed in patients with suspected upper tract urothelial carcinoma (UTUC). In a bi-center retrospective study we compared the results of the new tissue handling technique (group 1) with the standard technique (group 2). In the new technique, to achieve maximal tissue preservation, the specimen is mounted on filter paper prior to embedding in paraffin. Multivariate analysis was performed to determine which factors are associated with optimal histological results. We further compared the biopsies with the final specimen in a subgroup of patients who underwent nephroureterectomy (NU). Of 55 ureteroscopic biopsies, 1 biopsy from group 1 (new technique) and 3 biopsies from group 2 (standard technique) were inadequate for pathological examination. 51 UTUC specimens were analyzed. Tumor grade and stage were determined in 85% and 63% of the patients in group 1 and in 83% and 25% of group 2 (p=0.85 and p=0.007). Orientation was preserved in 82% of group 1 and 42% of group 2 (p=0.003). On multivariate analysis biopsy technique and biopsy diameter were found to predict stage determination (p=0.01 and p=0.007) and tissue orientation (p=0.005 and p=0.04). Among patients who underwent NU, stage concordance between the biopsy and final pathology was observed in 56% and 27% of the patients in group 1 and 2, respectively. The new processing technique for small UTUC forceps biopsies decreases the rate of biopsies with insufficient material and improves biopsy interpretation.

Upper urinary tract disease: what we know today and unmet needs

Purpose

Upper tract urothelial carcinoma (UTUC) is a rare and poorly investigated disease. Intense collaborative efforts have increased our knowledge and improved the management of the disease. The objective of this review was to discuss recent advances and unmet needs in UTUC.

Methods

A non-systematic Medline/PubMed literature search was performed on UTUC using the terms “upper tract urothelial carcinoma” with different combinations of keywords. Original articles, reviews and editorials in English language were selected based on their clinical relevance.

Results

UTUC is a disease with specific epidemiologic and risk factors different to urothelial carcinoma of the bladder (UCB). Similarly to UCB, smoking increases the risk of UTUC and worsens its prognosis, whereas aristolochic acid (AA) exposure and mismatch repair genes abnormality are UTUC specific risk factors. A growing understanding of biological pathways involved in the tumorigenesis of UTUC has led to the identification of promising prognostic/predictive biomarkers. Risk stratification of UTUC is difficult due to limitations in staging and grading. Modern imaging and endoscopy have improved clinical decision-making, and allowed kidney-sparing management and surveillance in favorable-risk tumors. In high-risk tumors, radical nephroureterectomy (RNU) remains the standard. Complete removal of the intramural ureter is necessary with inferiority of endoscopic management. Post-RNU intravesical instillation has been shown to decrease bladder cancer recurrence rates. While the role of neoadjuvant cisplatin based combination chemotherapy and lymphadenectomy are not clearly established, the body of evidence suggests a survival benefit to these. There is currently no evidence for adjuvant chemotherapy (AC) in UTUC.

Conclusions

Despite growing interest and understanding of UTUC, its management remains challenging, requiring further high quality multicenter collaborations. Accurate risk estimation is necessary to avoid unnecessary RNUs while advances in technology are still required for optimal kidney-sparing approaches.