Comparison of 3 upper tract anticarcinogenic agent delivery techniques in an ex vivo porcine model

The Role of Local Agents for the Treatment of Localized Upper Tract Urothelial Carcinoma: A Review of the Current Evidence

Kidney-sparing surgery (KSS) for upper urinary tract urothelial carcinoma (UTUC) is a promising alternative to radical nephroureterectomy, especially for low-risk cases. However, due to the established risk of ipsilateral UTUC recurrence caused by the implantation of floating neoplastic cells after endoscopic resection, adjuvant endocavitary (endoureteral) instillations have been proposed. Instillation therapy may be also used as primary treatment for UTUC. The two most studied drugs that have been evaluated in both the adjuvant and primary setting of endocavitary instillation are mitomycin C and Bacillus Calmette-Guerin. The current paper provides an overview of the endocavitary treatments for UTUC, focusing on methods of administration, novel formulations, oncologic outcomes (in terms of endocavitary recurrence and progression), as well as on complications. In particular, the role of UGN-101 as a primary chemoablative treatment of primary noninvasive, endoscopically unresectable, low-grade, UTUC has been analysed. The drug achieved a complete response rate of 58% after the induction cycle, with a durable response independently of the maintenance cycle. The cumulative experience on the role of UUT instillation therapy appears encouraging; however, no definitive conclusions can be drawn about its therapeutic benefit. Given the current state of the art, any decision to administer adjuvant endoureteral therapy for UTUC should be carefully weighed against the potential adverse events. Nevertheless, newer investigations that improve visualization during ureteroscopy, genomic characterization, novel drugs and innovative strategies of improved drug delivery are under evaluation. The landscape of KSS for the treatment of the UTUC is evolving and seems promising.

Novel treatment of upper tract urothelial carcinoma in situ with docetaxel in BCG refractory patients

INTRODUCTION

Patients with upper-tract carcinoma in situ (UT-CIS) that have failed treatment with BCG are recommended for radical nephroureterectomy (RNU). We describe a cohort of patients with BCG-refractory UT-CIS that were treated with docetaxel, a novel agent in the approach to topical therapy.

METHODS

Patients with pathologically proven UT-CIS from 2012 to 2020 with an imperative indication for organ preservation and history of BCG-refractory disease were included. Each patient underwent ureteroscopy with biopsy and selective cytology pre- and postinduction, and after each maintenance course. Complete response (CR) was defined as the absence of visualized lesions on ureteroscopy, negative selective cytology, and absence of clinical progression. No response (NR) was defined as persistence of lesions after induction or absence of visualized lesions with persistently positive cytology.

RESULTS

Seven patients and 10 renal units were treated. Six of the 10 renal units had initial CR (60%). Three patients with NR went on to have RNU, one of which subsequently died due to cancer-specific mortality. One patient with bilateral disease had NR in 10 renal unit and cure in the other. This patient subsequently developed recurrence in his remaining renal unit. A second patient had CR in both kidneys for 6 years, but 1 year after finishing maintenance regimen developed HG disease in 1 ureter. Average follow-up was 33 months.

CONCLUSION

This study demonstrates efficacy of docetaxel as a treatment option for patients with UT-CIS with a contraindication to RNU after failing BCG. Response rates of 60% appear to be similar to those of BCG-refractory bladder CIS.

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.

Consultation on UTUC, Stockholm 2018: aspects of treatment

Purpose

To provide an overview of treatment modalities for management of upper tract urothelial carcinoma (UTUC).

Methods

In accordance with the standards for a scoping review, data presentation and discussion at the Consultation on UTUC in Stockholm, 6–7 September 2018, consensus was reached on the latest and most important treatment recommendations for UTUC. Using Pubmed, Web of Science, and Embase, publications were selected based on quality, clinical relevance, and level of evidence.

Results

Kidney-sparing surgery should be attempted for low-grade UTUC. Radical nephroureterectomy with bladder cuff excision is first option for high-grade disease. Post-operative bladder instillation of chemotherapy should be offered after RNU to reduce intravesical recurrence rate. Identification of tumor grade and stage is crucial when selecting treatment. Ureteroscopic management of low-grade and non-invasive UTUC achieves disease-free survival similar to that offered by radical nephroureterectomy but seems to be a risk factor for intravesical recurrence. Lymphadenectomy appears important for high-risk disease, although the therapeutic benefit needs further validation. There is little evidence supporting use of Bacillus Calmette–Guérin (BCG) and mitomycin C as monotherapy and adjuvant treatment in UTUC. A randomized clinical trial has indicated that platin-based chemotherapy for invasive UTUC improves disease-free survival, suggesting that adjuvant chemotherapy should be considered standard care for ≥ T2 N0–3M0 disease.

Conclusions

Risk stratification assessment is feasible and mandatory in UTUC. Identification of tumor grade and stage is essential for optimal treatment selection. Kidney-sparing surgery should be offered in low-risk disease, whereas radical nephroureterectomy and adjuvant chemotherapy should be considered in high-risk disease.

[Instillation therapies for urothelial carcinoma of the upper urinary tract]

Traditionally, urothelial carcinoma of the upper urinary tract was a clear indication for radical nephroureterectomy with bladder cuff excision. It has been shown that in well-selected patients and depending on tumor stage, a kidney-sparing approach can be pursued with good oncological outcome and equivalent to the radical approach. The prevention of local and bladder recurrences is an important factor. Instillation therapies with bacillus Calmette-Guérin and/or mitomycin C have been successfully used to this end. Due to the low incidence of upper tract urothelial cancer and due to the usually retrospective nature of existing literature, however, data is limited. In this article, we provide a review of the indication, technical execution and results of instillation therapies of the upper urinary tract.

Intracavitary therapies for upper tract urothelial carcinoma

INTRODUCTION

While radical nephroureterectomy remains the gold-standard for upper tract urothelial carcinoma (UTUC), there is a growing push for organ-sparing therapy in low-risk disease. Herein we review the use of intracavitary topical therapy for treatment of UTUC. Areas covered: A PubMed search was performed for studies pertaining to upper tract urothelial carcinoma, with 236 articles reviewed, and distilled for content pertinent to intracavitary therapy for UTUC. Topics discussed include agents used for management of UTUC, most commonly BCG, as well as techniques for administration. Additionally, we review the evidence for curative treatment for Cis versus adjuvant therapy for Ta/T1 disease. Finally, we discuss emerging technologies to improve agent delivery and efficacy in the upper tract. Expert commentary: No significant advances have occurred in topical management of UTUC in the past 2 decades. However, advances in diagnostic techniques such as modern ureteroscopes, and improved diagnostic imaging at the time of ureteroscopy may help improve our patient selection. Additional advances in topical therapy focused on increasing the duration of contact between agent delivered and the upper tract urothelium offer hope that a new leap forward in topical therapy is on the horizon.

Which is best method for instillation of topical therapy to the upper urinary tract? An in vivo porcine study to evaluate three delivery methods

Purpose:

To compare the staining intensity of the upper urinary tract (UUT) urothelium among three UUT delivery methods in an in vivo porcine model.

Materials and methods:

A fluorescent dye solution (indigo carmine) was delivered to the UUT via three different methods: antegrade perfusion, vesico-ureteral reflux via in-dwelling ureteric stent and retrograde perfusion via a 5F open-ended ureteral catheter. Twelve renal units were tested with 4 in each method. After a 2-hour delivery time, the renal-ureter units were harvested en bloc. Time from harvesting to analysis was also standardised to be 2 hours in each arm. Three urothelium samples of the same weight and size were taken from each of the 6 pre-defined points (upper pole, mid pole, lower pole, renal pelvis, mid ureter and distal ureter) and the amount of fluorescence was measured with a spectrometer.

Results:

The mean fluorescence detected at all 6 predefined points of the UUT urothelium was the highest for the retrograde method. This was statistically significant with p-value less than <0.05 at all 6 points.

Conclusions:

Retrograde infusion of UUT by an open ended ureteral catheter resulted in highest mean fluorescence detected at all 6 pre-defined points of the UUT urothelium compared to antegrade infusion and vesico-ureteral reflux via indwelling ureteric stents indicating retrograde method ideal for topical therapy throughout the UUT urothelium. More clinical studies are needed to demonstrate if retrograde method could lead to better clinical outcomes compared to the other two methods.

Endoscopic Approaches to Upper Tract Urothelial Carcinoma

A select group of patients with upper tract urothelial carcinoma (UTUC) may meet indications for endoscopic management. Strategies for disease management are provided, based on a comprehensive review of the data using PubMed and Medline databases and marrying this with our experience with endoscopic management of UTUC. Endoscopic management of UTUC via retrograde or antegrade approaches is a viable treatment option for appropriately selected patients with low-risk UTUC, including those with low-grade, low-volume, and solitary tumors. However, recurrence risk limits these procedures to compliant patients under a vigilant surveillance program. Efficacious adjuvant therapies are needed to reduce local recurrences.

Evaluation of a New Design of Antireflux-biodegradable Ureteral Stent in Animal Model

OBJECTIVE

To determine the effects in urinary tract of a new antireflux-biodegradable ureteral stent.

MATERIALS AND METHODS

Thirty six ureters belonging to 24 pigs were used. The study began with endoscopic, nephrosonographic, and fluoroscopic assessments. Three study groups of ureters (n = 12) were then specified. In group I, a biodegradable antireflux ureteral stent (BDG-ARS) was inserted in the right ureter of 12 pigs. Group II comprised the left ureter of the same animals, in which a double-pigtail stent was placed for 6 weeks. Group III ureters, belonging to 12 additional animals, were subjected to a ureteropelvic junction obstruction model that was then treated by endopyelotomy and stenting with BDG-ARS. Follow-ups were performed at 3-6 weeks and at 5 months.

RESULTS

None of the ureters receiving the BDG-ARS showed any evidence of vesicoureteral reflux (VUR). BDG-ARS degradation took place in a controlled and predictable fashion from the third to the sixth weeks, and no obstructive fragments appeared. No differences were found between groups I and II regarding passive ureteral dilation, but significant differences were found regarding VUR and ureteral orifice damage. BDG-ARS always maintained distal ureteral peristalsis. BDG-ARS in group III showed a 50% positive urine culture rate and a 16.6% migration rate in both BDG-ARS groups.

CONCLUSION

BDG-ARS avoided VUR and bladder trigone irritation. In addition, this polymer combination and stent-braided design achieved a consistent biodegradation rate with no obstructive fragments and with uniform degradation between the third and the sixth weeks. Consequently, morbidity associated with ureteral stents might be reduced.

Induction and Maintenance Adjuvant Mitomycin C Topical Therapy for Upper Tract Urothelial Carcinoma: Tolerability and Intermediate Term Outcomes

PURPOSE

Endoscopic management of upper tract urothelial carcinoma (UTUC) is associated with higher recurrences, which could be reduced by application of topical therapy. Adjuvant induction Bacillus Calmette-Guerin has shown inferior outcomes for UTUC compared to bladder cancer, and maintenance regimens for UTUC are unexplored. We report on the efficacy, safety, and tolerability of Mitomycin C (MMC) induction and maintenance adjuvant topical therapy for UTUC.

MATERIALS AND METHODS

Patients with UTUC who received adjuvant topical therapy after complete endoscopic control of Ta/T1 tumors were retrospectively reviewed. Patients were treated using percutaneous nephrostomy tube (NT) or cystoscopically placed weekly ureteral catheters, per patient preference, and all patients were offered induction and maintenance. Standardized follow-up of every 3 months in the first year, then at a minimum every 6 months, with ureteroscopy and at least annual CT, was performed. Primary outcomes were recurrence-free, progression-free, nephroureterectomy-free rate and cancer-specific and overall survival. Secondary outcomes were safety and treatment tolerability.

RESULTS

Twenty-seven patients with 28 renal units received adjuvant topical therapy from January 2008 to March 2015. Median follow-up was 19 months (range 7-92). Three year recurrence-free, progression-free, and nephroureterectomy-free survival rates were 60% [confidence interval (95% CI): 42, 86%], 80% [95% CI: 64, 100%], and 76% [95% CI: 60, 97%]. Cancer-specific mortality rate was 0%, and 3-year overall survival was 92.9%. Nine patients experienced adverse outcomes, all related to interventions and none related to systemic toxicity.

CONCLUSIONS

Induction and maintenance adjuvant topical MMC for endoscopically resected UTUC is feasible, well tolerated and shows promising intermediate term data on recurrence, progression, and nephroureterectomy-free survival.

Sustained-release Formulation of Mitomycin C to the Upper Urinary Tract Using a Thermosensitive Polymer: A Preclinical Study

OBJECTIVE

To evaluate the safety and feasibility of single and serial instillations of MitoGel into the upper urinary tract using a preclinical swine animal model. MitoGel is a novel sustained release formulation of mitomycin C (MMC) based on RTGel, a proprietary thermosensitive hydrogel technology. MitoGel is liquid at cold temperatures and solidifies to gel state at body temperature. It is intended as a treatment for upper tract urothelial carcinoma, given its ability to provide sustained release of MMC in the upper urinary tract.

MATERIALS AND METHODS

We utilized 23 pigs in a 3-phase design. All animals underwent bilateral nephrostomy tube placement. During phase 1, 3 animals underwent antegrade RTGel instillation, imaging, and euthanasia within 12 hours. In phase 2, 10 pigs underwent single antegrade instillation, unilateral nephrectomy 3 days following instillation, and contralateral nephrectomy and euthanasia 30 days following instillation. During phase 3, 10 animals underwent 6 instillations over 3 weeks, followed by bilateral nephrectomy and necropsy 30 days postinstillation. MitoGel (2 mg/mL and 4 mg/mL), aqueous MMC (2 mg/mL and 4 mg/mL), and RTGel alone were evaluated.

RESULTS

MitoGel remained visible within the pelvicalyceal system on fluoroscopic and computed tomography imaging for 4-6 hours. MMC plasma levels were well within acceptable safety thresholds. There was no evidence of urinary obstruction, acute kidney injury, sepsis, or myelosuppression. Histologic changes in the urinary system were mild and transient.

CONCLUSION

Antegrade MitoGel delivery to the pelvicalyceal system of Yorkshire swine is feasible and safe. Further evaluation of MitoGel in human clinical trials is warranted.