5-aminolevulinic acid-mediated photodynamic diagnosis using fluorescence ureterorenoscopy for urinary upper tract urothelial carcinoma ∼Preliminary prospective single centre trial∼

Diagnosing upper tract urothelial carcinoma: A review of the role of diagnostic ureteroscopy and novel developments over last two decades

Objective

The role of ureteroscopy in the diagnosis of upper tract urothelial carcinoma is yet to be fully determined. We aimed to provide an up to date evaluation of its role and the emerging technologies in the field.

Methods

A literature search of the last two decades (from 24th May, 2001 to 24th May, 2021) was carried out identifying 147 papers for potential inclusion within this narrative review.

Results

Diagnostic ureteroscopy is undeniably useful in its ability to visualise and biopsy indeterminate lesions, and to risk stratify malignant lesions that may be suitable for kidney sparing surgery. However, an increased risk of intravesical recurrence following nephroureterectomy when a prior diagnostic ureteroscopy has been performed, inadequate sampling at biopsy, complications from the procedure, and difficult ureteric access are all potential drawbacks. Furthermore, whilst generally an accurate diagnostic procedure, it risks missing carcinoma in-situ lesions. Despite this, evidence shows that routine use of ureteroscopy changes the management of patients in a large proportion of cases, preventing unnecessary surgery or facilitating kidney sparing surgery. The overall rate of complications is low, and improved biopsy techniques and the use of tissue biomarkers for improved staging and grading are encouraging. The risks of delays to definitive management and post-ureteroscopy intravesical recurrence do not seem to affect survival, and trials are in progress to determine whether intravesical therapy can mitigate the latter. Further promising techniques are being investigated to improve shortcomings, particularly in relation to improved diagnosis of carcinoma in situ and preoperative staging.

Conclusion

Ureteroscopy has a role in the diagnosis of upper tract malignancy, though whether it should be used routinely is yet to be determined.

Upper Tract Urothelial Carcinoma (UTUC) Diagnosis and Risk Stratification: A Comprehensive Review

Diagnosis and risk stratification are cornerstones of therapeutic decisions in the management of patients with upper tract urothelial carcinoma (UTUC). Diagnostic modalities provide data that can be integrated, to provide nomograms and stratification tools to predict survival and adverse outcomes. This study reviews cytology, ureterorenoscopy and the novel tools and techniques used with it (including photodynamic diagnosis, narrow-band imaging, optical coherence tomography, and confocal laser endomicroscopy), and biopsy. Imaging modalities and novel biomarkers are discussed in another article. Patient- and tumor-related prognostic factors, their association with survival indices, and their roles in different scores and predictive tools are discussed. Patient-related factors include age, sex, ethnicity, tobacco consumption, surgical delay, sarcopenia, nutritional status, and several blood-based markers. Tumor-related prognosticators comprise stage, grade, presentation, location, multifocality, size, lymphovascular invasion, surgical margins, lymph node status, mutational landscape, architecture, histologic variants, and tumor-stroma ratio. The accuracy and validation of pre-operative predictive tools, which incorporate various prognosticators to predict the risk of muscle-invasive or non-organ confined disease, and help to decide on the surgery type (radical nephroureterectomy, or kidney-sparing procedures) are also investigated. Post-operative nomograms, which help decide on adjuvant chemotherapy and plan follow-up are explored. Finally, a revision of the current stratification of UTUC patients is endorsed.

Learning from the past and present to change the future: Endoscopic management of upper urinary tract urothelial carcinoma

Current guidelines recommend endoscopic management (EM) for patients with low-risk upper urinary tract urothelial carcinoma, as well as those with an imperative indication. However, regardless of the tumor risk, radical nephroureterectomy is still mainly performed worldwide despite the benefits of EM, such as renal function maintenance, no hemodialysis requirement, and treatment cost reduction. This might be explained by the association of EM with a high risk of local recurrence and progression. Furthermore, the need for rigorous patient selection and close surveillance following EM may be relevant. Nevertheless, recent developments in diagnostic modalities, pathological evaluation, surgical devices and techniques, and intracavitary regimens have been reported, which may contribute to improved risk stratification and treatments with superior oncological outcomes. In this review, considering recent advances in endourology and oncology, we propose novel treatment strategies for optimal EM.

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.

Suppression of angiotensin converting enzyme 2, a host receptor for SARS-CoV-2 infection, using 5-aminolevulinic acid in vitro

Angiotensin converting enzyme 2 (ACE2), an entry receptor found on the surface of host cells, is believed to be detrimental to the infectious capability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Scientists have been working on finding a cure since its outbreak with limited success. In this study, we evaluated the potential of 5-aminolevulinic acid hydrochloride (ALA) in suppressing ACE2 expression of host cells. ACE2 expression and the production of intracellular porphyrins following ALA administration were carried out. We observed the reduction of ACE2 expression and intracellular porphyrins following ALA administration. ALA suppressed the ACE2 expression in host cells which might prevent binding of SARS-CoV-2 to host cells. Co-administration of ALA and sodium ferrous citrate (SFC) resulted in a further decrease in ACE2 expression and increase in intracellular heme level. This suggests that the suppression of ACE2 expression by ALA might occur through heme production. We found that the inhibition of heme oxygenase-1 (HO-1), which is involved in heme degradation, also resulted in decrease in ACE2 expression, suggesting a potential role of HO-1 in suppressing ACE2 as well. In conclusion, we speculate that ALA, together with SFC administration, might serve as a potential therapeutic approach in reducing SARS-CoV-2 infectivity through suppression of ACE2 expression.

French AFU Cancer Committee Guidelines - Update 2022-2024: Upper urinary tract urothelial cancer (UTUC)

INTRODUCTION

The aim was to propose an update of the French Urology Association Cancer Committee (ccAFU) Recommendations on the management of upper urinary tract urothelial carcinomas (UUT-UC).

METHODS

A systematic Medline search was performed between 2020 and 2022, taking account of the diagnosis, treatment options and follow-up of UUT-UC, while evaluating the references with their levels of evidence.

RESULTS

The diagnosis of this rare pathology is based on CTU acquisition during excretion and flexible ureterorenoscopy with histological biopsies. Radical nephroureterectomy (RNU) remains the gold standard for surgical treatment. Nevertheless conservative treatment can be discussed for low risk lesions: tumour of low-grade, with no infiltration on imaging, unifocal<2cm, eligible for full treatment therefore requiring close endoscopic surveillance by flexible ureteroscopy in compliant patients. After RNU, postoperative instillation of chemotherapy is recommended to reduce the risk of recurrence in the bladder. Adjuvant chemotherapy has shown clinical benefits compared to surveillance after RNU for tumours (pT2-T4 N0-3 M0).

CONCLUSION

These updated recommendations should contribute to improving not only patients' level of care, but also the diagnosis and decision-making concerning treatment for UUT-UC.

5-Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence Imaging for Tumor Detection: Recent Advances and Challenges

5-Aminolevulinic acid (5-ALA) is a natural amino acid and a precursor of heme and chlorophyll. Exogenously administered 5-ALA is metabolized into protoporphyrin IX (PpIX). PpIX accumulates in cancer cells because of the low activity of ferrochelatase, an enzyme that metabolizes PpIX to heme. High expression of 5-ALA influx transporters, such as peptide transporters 1/2, in cancer cells also enhances PpIX production. Because PpIX radiates red fluorescence when excited with blue/violet light, 5-ALA has been used for the visualization of various tumors. 5-ALA photodynamic diagnosis (PDD) has been shown to improve the tumor removal rate in high-grade gliomas and non-muscular invasive bladder cancers. However, 5-ALA PDD remains a challenge as a diagnostic method because tissue autofluorescence interferes with PpIX signals in cases where tumors emit only weak signals, and non-tumorous lesions, such as inflammatory sites, tend to emit PpIX fluorescence. Here, we review the current outline of 5-ALA PDD and strategies for improving its diagnostic applicability for tumor detection, focusing on optical techniques and 5-ALA metabolic pathways in both viable and necrotic tumor tissues.

A prospective, single-arm trial of fluorescent ureteroscopy-assisted thulium-holmium:YAG dual laser ablation for upper urinary tract cancer: Study protocol of the FLUAM trial

Background

Latest guidelines recommend kidney-sparing management as the primary treatment option for selected patients with upper urinary tract urothelial carcinoma (UTUC). One of the biggest issues of ureteroscopic laser ablation (ULA) is a high rate of surgical site recurrence, which is largely attributed to residual lesions at the initial ULA. Another clinical issue is a significant lack of non-invasive reliable detection tools of urinary recurrent tumors in this treatment setting.

Methods

The FLUAM trial is a prospective, single-center, single-arm pilot trial to investigate the efficacy of 5-aminolevulinic acid-mediated photodynamic diagnosis (ALA-PDD)-assisted ULA for localized UTUC and the usefulness of the UroVysion® assay (multiprobe fluorescence in situ hybridization) as a monitoring test after the kidney-sparing treatment. After the screening and registration, a total of 20 patients with localized UTUC will undergo the initial ALA-PDD-assisted ULA followed by the second look ALA-PDD-assisted ureteroscopic examination. The primary endpoint is progression-free survival. Secondary endpoints include patient reported outcomes, diagnostic accuracy of UroVysion assay to detect tumor recurrence, adverse events, and safety of the intervention.

Conclusion

The goal of this trial is to determine the potential benefit of ALA-PDD assistance in patients who undergo the ULA. The evidence of this novel technique is still limited. The results are expected to change the standard of care and lead to better management of localized UTUC.

Trial registration

This clinical trial was prospectively registered with the Japan Registry of Clinical Trials on 23 June 2021. The reference number is jRCTs051210042, nara0023 (Certified Review Board of Nara Medical University).

Current Status of Photodynamic Technology for Urothelial Cancer

5‐Aminolevulinic acid is a new‐generation photosensitizer with high tumor specificity. It has been used successfully in the diagnosis, treatment, and screening of urological cancers including bladder cancer; specifically, it has been used in photodynamic diagnosis to detect tumors by illuminating the lesion with a specific wavelength of light to produce fluorescence in the lesion after administration of 5‐aminolevulinic acid, in photodynamic therapy, which induces tumor cell death via production of cytotoxic reactive oxygen species, and in photodynamic screening, in which porphyrin excretion in the blood and urine is used as a tumor biomarker after administration of 5‐aminolevulinic acid. In addition to these applications in urological cancers, 5‐aminolevulinic acid–based photodynamic technology is expected to be used as a novel strategy for a large number of cancer types because it is based on a property of cancer cells known as the Warburg effect, which is a basic biological property that is common across all cancers.

[French ccAFU guidelines - update 2020-2022: upper urinary tract urothelial carcinoma]

INTRODUCTION

-The purpose was to propose an update of the French guidelines from the national committee ccAFU on upper tract urothelial carcinomas (UTUC).

METHODS

- A systematic Medline search was performed between 2018 and 2020, as regards diagnosis, options of treatment and follow-up of UTUC, to evaluate different references with levels of evidence.

RESULTS

- The diagnosis of this rare pathology is based on CT-scan acquisition during excretion and ureteroscopy with histological biopsies. Radical nephroureterectomy (RNU) remains the gold standard for surgical treatment, nevertheless a conservative endoscopic approach can be proposed for low risk lesion: unifocal tumor, possible complete resection and low grade and absence of invasion on CT-scan. Close monitoring with endoscopic follow-up (flexible ureteroscopy) in compliant patients is therefore necessary. After RNU, bladder instillation of chemotherapy is recommended to reduce risk of bladder recurrence. A systemic chemotherapy is recommended after RNU in pT2-T4 N0-3 M0 disease.

CONCLUSION

- These updated guidelines will contribute to increase the level of urological care for diagnosis and treatment for UTUC.

Developments in Vascular-Targeted Photodynamic Therapy for Urologic Malignancies

With improved understanding of cancer biology and technical advancements in non-invasive management of urological malignancies, there is renewed interest in photodynamic therapy (PDT) as a means of focal cancer treatment. The application of PDT has also broadened as a result of development of better-tolerated and more effective photosensitizers. Vascular-targeted PDT (VTP) using padeliporfin, which is a water-soluble chlorophyll derivative, allows for tumor-specific cytotoxicity and has demonstrated efficacy in the management of urologic malignancies. Herein, we describe the evolution of photodynamic therapy in urologic oncology and the role of VTP in emerging treatment paradigms.

Diagnostic accuracy of photodynamic diagnosis for upper urinary tract urothelial carcinoma: A systematic review and meta-analysis

BACKGROUND

This study aimed to evaluate the effectiveness of photodynamic diagnosis (PDD) for upper urinary tract urothelial carcinoma (UTUC) by performing a meta-analysis.

METHOD

Relevant articles were retrieved from the Cochrane Library, PubMed, and Embase databases. Studies evaluating the accuracy of PDD for the diagnosis of upper UTUC were included. The pooled sensitivity, specificity, and area under the curve (AUC) were calculated by STATA 16.0 at the per-lesion level.

RESULTS

Six studies with 289 lesions were included in this systematic review and meta-analysis. The pooled results showed that PDD can differentiate upper UTUC from benign lesions with a sensitivity of 0.96 (95 % confidence interval: 0.85-0.99) and a specificity of 0.86 (95 % confidence interval: [0.64-0.95]; AUC, 0.97). Compared with white-light ureterorenoscopy, PDD can significantly improve the additional detection rate of UTUC (RR 0.16, 95 % CI 0.07-0.34 P = 0.000).

CONCLUSIONS

PDD is a valid technique that improves the diagnostic accuracy of UTUC compared with standard white-light ureterorenoscopy at the per-lesion level. PDD is a promising endoscopic technique for upper UTUC.

Photodynamic diagnosis and therapy for urothelial carcinoma and prostate cancer: new imaging technology and therapy

Photodynamic technology using light-sensitive and fluorescent substances has an important role in an accurate diagnosis for a variety of malignancies, including bladder cancer and prostate cancer. Light-sensitive and fluorescent substances accumulate specifically in tumor cells compared to normal tissue, and by light irradiation and excitation at each specific wavelength, tumor lesion, blood flow, lymph node and so on show fluorescence. 5-Aminolevulinic acid (ALA) is converted to protoporphyrin IX (PpIX) into mitochondria. PpIX is excited by blue light, red fluorescence is emitted in the mitochondria. This phenomenon is the mechanism of ALA-mediated photodynamic diagnosis (ALA-PDD). ALA-PDD has made it possible to visualize smaller lesions and flat lesions that were previously difficult to visualize by endoscope using a white-light source. So accurate diagnosis and complete resection become possible during operation. The accumulation of PpIX in the mitochondria also induces direct mitochondrial damage and subsequent cell death by red and green light. This biological reaction is the ALA-mediate photodynamic therapy (ALA-PDT). ALA-PDT has been developed as a modality for minimum invasive cancer treatment that utilizes low-energy light and photosensitizer. Vascular-activated photosensitizer induces rapid tumor ablation by PDT involving direct tumor cell killing as well as damage to the exposed microvasculature. We summarize the clinical outcomes of PDD and PDT for urothelial carcinoma and prostate cancer.