Combined intravesical hyperthermia and mitomycin chemotherapy: a preliminary in vivo study

The Efficacy and Safety of Hyperthermia Intravesical Chemotherapy in the Treatment of Non-Muscle-Invasive Bladder Cancer: A Meta-Analysis

INTRODUCTION

The current treatment of non-muscle-invasive bladder cancer is suboptimal. However, in recent years, hyperthermia intravesical chemotherapy (HIVEC) has emerged as a more effective alternative to conventional bladder perfusion. This novel treatment approach appears to have a similar therapeutic effect as Bacillus Calmette-Guérin (BCG) perfusion. This study aims to evaluate the safety and effectiveness of HIVEC compared to conventional bladder perfusion chemotherapy for non-muscle-invasive bladder cancer. Additionally, it aims to evaluate the safety and effectiveness of HIVEC in comparison to BCG perfusion therapy for non-muscle-invasive bladder cancer.

METHODS

We conducted a comprehensive search of PubMed, Embase, Cochrane Library, and Web of Science databases to gather relevant studies on HIVEC for non-muscle-invasive bladder cancer. The analysis of the collected data was carried out using RevMan 5.3 software.

RESULTS

A total of 8 randomized controlled trials were included in this meta-analysis, involving 1,203 patients. Among them, 629 cases received HIVEC, 419 cases received conventional bladder perfusion chemotherapy with mitomycin C, and 155 cases received BCG. The combined analysis revealed that the recurrence rate of bladder hyperthermic perfusion was significantly lower than that of conventional perfusion chemotherapy (RR = 0.65, 95% CI: 0.52, 0.82, p = 0.0003). However, there was no significant difference in recurrence rate between HIVEC and BCG perfusion (RR = 0.78, 95% CI: 0.56, 1.09, p = 0.14). Furthermore, no significant difference was found in the progression rate between the HIVEC group and either the conventional bladder chemotherapy group (RR = 1.08, 95% CI: 0.52, 2.26, p = 0.83) and the BCG perfusion group (RR = 0.48, 95% CI: 0.19, 1.25, p = 0.13). However, compared with the conventional bladder perfusion chemotherapy group, there was no significant statistical difference in adverse events between the bladder hyperthermia chemotherapy group and the conventional bladder perfusion chemotherapy group (RR 1.08, 95% CI: 0.80, 1.45, p = 0.63). No significant difference in the incidence of adverse events was observed between HIVEC and BCG perfusion (RR 1.03, 95% CI: 0.83, 1.29, p = 0.79).

CONCLUSION

The existing results indicate that HIVEC, when compared to conventional bladder perfusion chemotherapy, can lower the recurrence rate of non-muscle-invasive bladder cancer. However, it does not significantly affect the progression rate. There was no statistically significant difference observed in the incidence of adverse events between the use of HIVEC and conventional chemotherapy. Additionally, there was no significant difference in the recurrence rate, progression rate, and incidence of adverse events when compared to BCG.

Botulinum Toxin Therapy for Bladder Pain Syndrome/Interstitial Cystitis

Purpose of Review

Bladder pain syndrome (BPS)/interstitial cystitis (IC) can also be classified as either non-ulcerative or ulcerative, corresponding to the characteristic cystoscopic findings under hydrodistention. Promising therapeutic effects, including decreased bladder pain, have been reported from recent clinical trials using botulinum toxin A (BoNTA) for the treatment of BPS/IC. This review summarizes the current state of the literature on the underlying mechanisms of BoNTA therapy in BPS/IC as well as new forms of its application.

Recent Findings

BoNTA has its effect in the central nervous system in the afferent nerves as well as in the bladder wall. Besides the well-known effects of BoNTA in the nervous system, pain control as well as reduction of urinary urgency in BPS patients could be achieved by mast cell stabilization effecting histamine release as well as modulation of TRPV and PGE2 pathways, among other systems. In addition, new forms of BoNTA administration have focused on intravesical instillation of the drug in order to circumvent bladder wall injections. Hyperthermia, intravesical hydrogel, and lysosomes have been studied as new ways of BoNTA application in BPS/IC patients. From the available studies, bladder instillation of BoNTA in combination with EMDA is the most promising and effective novel approach.

Summary

The most promising novel application methods for BoNTA in patient with BPS/IC are bladder instillations. Future research needs to point out if bladder instillations with BoNTA with some form of bladder absorption enhancement such as hyperthermia or EMDA would be able to replace BoNTA injections in patients with BPS/IC

A scalable hyperthermic intravesical chemotherapy (HIVEC) setup for rat models of bladder cancer

Hyperthermic intravesical chemotherapy (HIVEC)—whereby the bladder is heated to ± 43 °C during a chemotherapy instillation—can improve outcomes of non-muscle invasive bladder cancer (NMIBC) treatments. Experiments in animal models are required to explore new hyperthermia based treatments. Existing HIVEC devices are not suitable for rodents or large-scale animal trials. We present a HIVEC setup compatible with orthotopic rat models. An externally heated chemotherapeutic solution is circulated in the bladder through a double-lumen catheter with flow rates controlled using a peristaltic pump. Temperature sensors in the inflow channel, bladder and outflow channel allow temperature monitoring and adjustments in real-time. At a constant flow rate of 2.5 mL/min the system rapidly reaches the desired bladder temperature of 42–43 °C with minimal variability throughout a one-hour treatment in a rat bladder phantom, as well as in euthanised and live rats. Mean intraluminal bladder temperatures were 42.92 °C (SD = 0.15 °C), 42.45 °C (SD = 0.37 °C) and 42.52 °C (SD = 0.09 °C) in the bladder phantom, euthanised, and live rats respectively. Thermal camera measurements showed homogenous heat distributions over the bladder wall. The setup provides well-controlled thermal dose and the upscaling needed for performing large scale HIVEC experiments in rats.

Heating technology for malignant tumors: a review

The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

Intravesical device-assisted therapies for non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC), the most prevalent type of bladder cancer, accounts for ~75% of bladder cancer diagnoses. This disease has a 50% risk of recurrence and 20% risk of progression within 5 years, despite the use of intravesical adjuvant treatments (such as BCG or mitomycin C) that are recommended by clinical guidelines. Intravesical device-assisted therapies, such as radiofrequency-induced thermochemotherapeutic effect (RITE), conductive hyperthermic chemotherapy, and electromotive drug administration (EMDA), have shown promising efficacy. These device-assisted treatments are an attractive alternative to BCG, as issues with supply have been a problem in some countries. RITE might be an effective treatment option for some patients who have experienced BCG failure and are not candidates for radical cystectomy. Data from trials using EMDA suggest that it is effective in high-risk disease but requires further validation, and results of randomized trials are eagerly awaited for conductive hyperthermic chemotherapy. Considerable heterogeneity in patient cohorts, treatment sessions, use of maintenance regimens, and single-arm study design makes it difficult to draw solid conclusions, although randomized controlled trials have been reported for RITE and EMDA.

Inducing intravesical hyperthermia of the ex-vivo porcine bladder wall: radiofrequency-induction versus recirculation using a custom-made device

INTRODUCTION

Several techniques can be used to treat intravesical chemohyperthermia (ChHT). We compared radiofrequency-induced hyperthermia (RF-HT) with conductive hyperthermia (C-HT) for their ability to induce bladder wall temperatures of >40.5 °C, the target temperature for ChHT.

MATERIALS AND METHODS

Fresh porcine bladders (n = 12) were placed in a temperature-controlled saline bath to simulate body temperature and circulation. HT was induced with RF-HT (43 °C) or C-HT (inflow temperature 44 and 46 °C) using a custom-made device. In two additional bladders, we varied intravesical solution and volume. Temperatures were recorded with a three-way catheter containing three mucosal and two urethral thermocouples (TCs) and a 915 MHz RF antenna, and with external TCs in the bladder wall at three different levels and three different locations.

RESULTS

Target temperature (40.5 °C) was reached in the submucosa at all locations by both techniques. In the detrusor, target temperature was reached by RF-HT at the bladder neck and side wall. C-HT₄₆ reached significantly higher submucosal temperatures at the side wall. The bladder dome seemed best heated by C-HT, although a high inflow temperature (46 vs. 44 °C) was required (ns). Intravesical saline resulted in higher temperatures than sterile water for RF-HT. A volume of 100 mL resulted in higher bladder dome temperatures for RF-HT, and higher bladder neck with lower dome temperatures for C-HT.

CONCLUSION

Our results indicate a slightly superior heating capacity for RF-HT compared to C-HT, whereas for the bladder dome, the reverse seems true. Comparative studies are warranted to evaluate whether HT efficacy differs between both techniques, with emphasis on tumor location.

Intravesical radiofrequency-induced hyperthermia combined with chemotherapy for non-muscle-invasive bladder cancer

Although many treatment modalities and schedules for non-muscle-invasive bladder cancer (NMIBC) exist, all yet prove to have limitations. Therefore the search for new forms of therapy continues. One of these forms consists of combining intravesical chemotherapy, typically mitomycin C (MMC), with hyperthermia achieved by a microwave-applicator. We aimed to review the current status of intravesical radiofrequency (RF) induced chemohyperthermia (CHT) for NMIBC with regard to efficacy, adverse-events (AEs) and its future perspective. A search for RF-induced CHT in MEDLINE, Embase, Cochrane and ClinicalTrials.gov databases was performed. Relevant conference abstracts were searched for manually. If applicable, experts on the area were consulted. Papers were selected based on abstract and title. A table of newly published clinical trials since 2011 was constructed. No meta-analysis could be performed based on these new papers. Efficacy proved to be better for RF-induced CHT compared to both MMC alone and bacillus Calmette-Guérin (BCG) instillations, with the latter being based on just one abstract of a randomised controlled trial. The AE rate in CHT is higher compared to MMC instillation, but is similar compared to BCG, albeit different in the type of AE. In almost all studies no severe AEs are reported. Although heterogeneity in methodology exists, RF-induced CHT seems promising. However, alternative methods of applying hyperthermia are starting to present their first results, imposing as effective options too. Intravesical RF-induced CHT may become an alternative for BCG instillation, and possibly for cystectomy, although further level 1 evidence is required for both reliable and reproducible data on efficacy and adverse events.

The role of hyperthermia as a treatment for non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) has a high tendency for recurrence and progression. Currently, all known intravesical agents are associated with adverse effects (AEs) and limited efficacy. The combination of hyperthermia (HT) with intravesical Mitomycin C (MMC) chemotherapy has been shown to improve outcomes. The added efficacy of HT to MMC was first shown in preclinical studies. The reports on patients with NMIBC have indicated that the treatment is safe and well tolerated. Several clinical studies reported the efficacy of radiofrequency-induced chemotherapy effect (RITE) in the treatment of patients with NMIBC. This modality was shown to be superior to MMC alone. RITE was effective also in patients with high-risk NMIBC, including those who failed Bacillus Calmette-Guérin (BCG). This study provides an updated review of literature regarding the use of RITE in patients with NMIBC.

The effect of thermochemotherapy with mitomycin C on normal bladder urothelium, an experimental study

PURPOSE

To investigate the effects of thermochemotherapy with mitomycin C (MMC) on normal rabbit bladder urothelium and to compare it with standard intravesical MMC and hyperthermia with normal saline.

METHODS

Twenty-four male New Zealand rabbits, with a mean weight of 2.7 kg (in weight of 2.1–4.3 kg), were divided into three groups, each containing eight rabbits. Thermotherapy with only normal saline was performed in the first group, standard intravesical MMC was performed in the second group, and thermotherapy with MMC was performed in the last group. A week after the primary procedure, total cystectomy was performed and tissue samples were evaluated.

RESULTS

The presence of epithelial vacuolar degeneration (p = 0.001), epithelial hyperplasia (p = 0.000), subepithelial fibrosis (p = 0.001) and hemorrhagic areas in the connective tissue (p = 0.002) was observed statistically significantly higher in the standard MMC group than in thermotherapy with normal saline group. There was almost a significant difference among standard MMC and normal saline group in terms of vascular congestion in the connective tissue (p = 0.08). Presence of epithelial vacuolar degeneration (p = 0.002), epithelial hyperplasia (p = 0.002), subepithelial fibrosis (p = 0.030), hemorrhagic areas (p = 0.011) and vascular congestion (p = 0.36) in the connective tissue was observed statistically significantly higher in the thermochemotherapy with MMC group than in standard intravesical MMC group. Polymorphonuclear cell infiltration was not considerable in any of the groups, and there was no significant difference between each groups (p = 0.140).

CONCLUSION

Administration of intravesical MMC causes a toxic effect on the normal urothelium of the bladder rather than an inflammatory reaction. Heating MMC significantly increased this effect.

The role of a combined regimen with intravesical chemotherapy and hyperthermia in the management of non-muscle-invasive bladder cancer: a systematic review

CONTEXT

Due to the suboptimal clinical outcomes of current therapies for non-muscle-invasive bladder cancer (NMIBC), the search for better therapeutic options continues. One option is chemohyperthermia (C-HT): microwave-induced hyperthermia (HT) with intravesical chemotherapy, typically mitomycin C (MMC). During the last 15 yr, the combined regimen has been tested in different clinical settings.

OBJECTIVE

To perform a systematic review to evaluate the efficacy of C-HT as a treatment for NMIBC.

EVIDENCE ACQUISITION

The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. An electronic search of the Medline, Embase, Cochrane Library, CancerLit, and ClinicalTrials.gov databases was undertaken. Relevant conference abstracts and urology journals were also searched manually. Two reviewers independently reviewed candidate studies for eligibility and abstracted data from studies that met inclusion criteria. The primary end point was time to recurrence. Secondary end points included time to progression, bladder preservation rate, and adverse event (AE) rate.

EVIDENCE SYNTHESIS

A total of 22 studies met inclusion criteria and underwent data extraction. When possible, data were combined using random effects meta-analytic techniques. Recurrence was seen 59% less after C-HT than after MMC alone. Due to short follow-up, no conclusions can be drawn about time to recurrence and progression. The overall bladder preservation rate after C-HT was 87.6%. This rate appeared higher than after MMC alone, but valid comparison studies were lacking. AEs were higher with C-HT than with MMC alone, but this difference was not statistically significant.

CONCLUSIONS

Published data suggest a 59% relative reduction in NMIBC recurrence when C-HT is compared with MMC alone. C-HT also appears to improve bladder preservation rate. However, due to a limited number of randomized trials and to heterogeneity in study design, definitive conclusions cannot be drawn. In the future, C-HT may become standard therapy for high-risk patients with recurrent tumors, for patients who are unsuitable for radical cystectomy, and in cases for which bacillus Calmette-Guérin treatment is contraindicated.

The influence of thermo-chemotherapy on bladder tumours: an immunohistochemical analysis

To study the influence of microwave induced thermo-chemotherapy on high-grade urothelial cell carcinomas. Five groups of each three patients were formed of whom initial biopsies and cystectomy samples were collected. Patients were treated 2 days prior to cystectomy with mitomycin-C (group 1), hyperthermia (group 2) or thermo-chemotherapy (group 3). Group 4 patients had been treated with a cycle of six thermo-chemotherapy treatments prior to cystectomy and group 5 patients served as control (no treatment). Tumour samples were stained with Haematoxylin and Eosin, monoclonal antibody Ki-67 and the monoclonal antibody p53. In six out of the nine patients treated with hyperthermia a decrease in proliferation activity in the tumour was found. Seven out of nine patients treated with hyperthermia showed a decrease in p53 activity. A decrease in proliferation activity and p53 activity illustrate the potential role of thermo-chemotherapy as a promising intravesical treatment.