Hexaminolevulinate Blue Light Cystoscopy: A Review of Its Use in the Diagnosis of Bladder Cancer

Targeting Bladder Urothelial Carcinoma with pHLIP-ICG and Inhibition of Urothelial Cancer Cell Proliferation by pHLIP-amanitin

Acidity is a useful biomarker for the targeting of metabolically active-cells in tumors. pH Low Insertion Peptides (pHLIPs) sense the pH at the surfaces of tumor cells and can facilitate intracellular delivery of cell-permeable and cell-impermeable cargo molecules. In this study we have shown the targeting of malignant lesions in human bladders by fluorescent pHLIP agents, intracellular delivery of amanitin toxin by pHLIP for the inhibition of urothelial cancer cell proliferation, and enhanced potency of pHLIP-amanitin for cancer cells with 17p loss, a mutation frequently present in urothelial cancers. Twenty-eight ex-vivo bladder specimens, from patients undergoing robotic assisted laparoscopic radical cystectomy for bladder cancer, were treated via intravesical incubation for 15-60 minutes with pHLIP conjugated to indocyanine green (ICG) or IR-800 near infrared fluorescent (NIRF) dyes at concentrations of 4-8 μM. White light cystoscopy identified 47/58 (81%) and NIRF pHLIP cystoscopy identified 57/58 (98.3%) of malignant lesions of different subtypes and stages selected for histopathological processing. pHLIP NIRF imaging improved diagnosis by 17.3% (p < 0.05). All carcinoma-in-situ cases missed by white light cystoscopy were targeted by pHLIP agents and were diagnosed by NIRF imaging. We also investigated the interactions of pHLIP-amanitin with urothelial cancer cells of different grades. pHLIP-amanitin produced concentration- and pH-dependent inhibition of the proliferation of urothelial cancer cells treated for 2 hrs at concentrations up to 4 μM. A 3-4x enhanced cytotoxicity of pHLIP-amanitin was observed for cells with a 17p loss after 2 hrs of treatment at pH6. Potentially, pHLIP technology may improve the management of urothelial cancers, including imaging of malignant lesions using pHLIP-ICG for diagnosis and surgery, and the use of pHLIP-amanitin for treatment of superficial bladder cancers via intravesical instillation.

Current Concepts in the Management of Muscle Invasive Bladder Cancer

Bladder cancer is the ninth most common cancer in the world. Twenty to twenty-five percent of all newly diagnosed bladder cancers are muscle invasive in nature, and further, 20-25% of patients who are diagnosed with high-risk non-muscle invasive disease will eventually progress to muscle invasive disease in due course of time irrespective of adjuvant intravesical therapies. Availability of newer imaging modalities improves appropriate identification of patients with muscle invasive disease. Radical cystectomy remains the mainstay of treatment for management of muscle invasive disease. Availability of neoadjuvant chemotherapy has improved overall survival. Risk stratification systems are now in consideration to identify patients who benefit maximally from neoadjuvant chemotherapy. Urinary diversion is a major cause of morbidity in these patients, and several strategies are being employed to reduce morbidity. In this article, we review available literature on various aspects of management of muscle invasive disease.

Evans blue-mediated white-light detection of non-muscle-invasive bladder cancer: A preclinical feasibility and safety study using a rat bladder urothelial cell carcinoma model

Photodynamic diagnosis (PDD) improves the detection of non-muscle-invasive bladder cancer (NMIBC). However, white-light (WL) cystoscopy remains the technique routinely used in urological clinics. A more cost-effective but equally performant alternative to PDD may encompass the use of an intense tumoritropic dye in combination with WL cystoscopy. Using a preclinical setting, we investigated the practical aspects of the use of Evans blue (EB) dye for the possible future detection of NMIBC using WL cystoscopy. A solution of 1 and 5 mM EB was instilled into healthy and AY-27 tumor-bearing rat bladders. The bladders were then rapidly dissected and the inner walls were inspected for EB using WL stereomicroscopy. EB present in the bladders and the plasma was also quantified using high performance liquid chromatography. To assess the effects of repeated instillations on normal rat bladders, EB was instilled for 7 consecutive days, after which time the bladder wall was investigated histologically. To gain insight into the mechanisms underlying the selective accumulation of EB in malignant urothelium, RNA sequencing of urothelial tissue and subsequent comparative analysis were performed, with a specific focus on cell adhesion. The concentrations of EB were substantially higher in malignant bladders compared with those in healthy bladders, matching the blue staining of the inner bladder wall observed by stereomicroscopy. EB was equally present in the plasma of healthy and tumor-bearing subjects, although at low concentrations. Importantly, EB did not cause any abnormalities in the urothelium after 7 days of repeated instillation in normal rats. RNA sequencing of the urothelium indicated an abnormal expression of several genes related to cell adhesion in malignant urothelium compared with the normal urothelium. Our findings may be important for future clinical developments in the field of diagnostics for bladder cancer. Implementing the more cost-effective protocol of EB instillations in combination with WL cystoscopy may offer a benefit to patients as well as the healthcare system.

Review of current optical diagnostic techniques for non-muscle-invasive bladder cancer

Introduction

Urinary bladder urothelial cell carcinoma is one of the most commonly diagnosed cancers in Europe. After prostate, lung and colon cancers, bladder cancer rates as the fourth most common cancer in men in the world.

Urinary bladder cancer detection, treatment, and staging have traditionally been based on an endoscopic examination – cystoscopy.

Material and methods

A Medline, and Web of Science database search was performed on September 2015 without setting time limits, using the terms ‘bladder cancer’ in conjunction with ‘cystoscopy’, ‘diagnosis’, ‘detection’, ‘fluorescence’, ‘blue-light’, ‘PDD’, ‘narrow band imaging’, ‘molecular imaging’, ‘optical coherence tomography’ or ‘confocal laser endomicroscopy’.

Results

The new imaging techniques can be classified according to their scope as macroscopic, microscopic, and molecular. Macroscopic techniques, such as narrow band imaging, are similar to white light cystoscopy; however, they help visualize even very minute lesions in the bladder mucosa by means of contrast enhancement.

Microscopic imaging techniques, such as optical coherence tomography and confocal laser endomicroscopy, provide high-resolution cross-sectional views of vesicular tissues, which resemble images obtained by histopathological examination. Therefore, these are referred as ‘optical biopsy’. Molecular imaging methods offer highly specific real-time visualization of cancer cells and their differentiation from healthy tissue, by combining optical imaging with fluorescent labeling of elements such as antibodies.

Conclusions

In this article we present a review of studies and literature concerning modern optical diagnostic techniques for non-muscle-invasive bladder cancer. We present available technology with its advantages and disadvantages, and studies regarding its effectiveness.

Vulvovaginal photodynamic therapy vs. topical corticosteroids in genital erosive lichen planus: a randomized controlled trial

BACKGROUND

Genital erosive lichen planus (GELP) in women is a chronic inflammatory disease characterized by painful vulval and vaginal erosions. Topical photodynamic therapy (PDT) is increasingly used in premalignant and malignant diseases and may have an effect in inflammatory diseases.

OBJECTIVES

To assess the feasibility, efficacy and safety of hexyl 5-aminolevulinate-hydrocloride (HAL)-PDT in GELP.

METHODS

Forty women, diagnosed with GELP at a specialized vulva clinic, were randomized to one session HAL-PDT in vulva and/or vagina (n = 20) or daily applications of clobetasol propionate 0·05% ointment in vulva and optional hydrocortisone acetate 1·0% foam in vagina for 6 weeks (n = 20). After 6 weeks, all patients were allowed to use topical corticosteroids as needed. Clinical examinations were performed at weeks 0, 6 and 24, using a clinical score developed for the study. All patients wrote a weekly log on pain, topical corticosteroid use and adverse events.

RESULTS

Three patients, all in the corticosteroid group, withdrew from the study after 1-3 weeks. The mean reduction in clinical scores was similar in the PDT group and the corticosteroid group; 25% vs. 22% after 6 weeks (P = 0·787) and 35% vs. 38% after 24 weeks (P = 0·801). The mean reduction in pain visual analogue scale scores was 38% vs. 55% after 6 weeks (P = 0·286) and 39% vs. 12% after 24 weeks (P = 0·452). Patients in the PDT group reported significantly less topical corticosteroid use during weeks 7-24 than those in the corticosteroid group. No major adverse events were reported.

CONCLUSIONS

Vulvovaginal HAL-PDT seems to be an effective and safe treatment for GELP.