The role of photodynamic therapy in the treatment of recurrent superficial bladder cancer

Development of Folic Acid-Conjugated and Methylene Blue-Adsorbed Au@TNA Nanoparticles for Enhanced Photodynamic Therapy of Bladder Cancer Cells

Photodynamic therapy (PDT) is a promising treatment for malignancy. However, the low molecular solubility of photosensitizers (PSs) with a low accumulation at borderline malignant potential lesions results in the tardy and ineffective management of recurrent urothelial carcinoma. Herein, we used tannic acid (TNA), a green precursor, to reduce HAuCl4 in order to generate Au@TNA core-shell nanoparticles. The photosensitizer methylene blue (MB) was subsequently adsorbed onto the surface of the Au@TNA nanoparticles, leading to the incorporation of a PS within the organic shell of the Au nanoparticle nanosupport, denoted as Au@TNA@MB nanoparticles (NPs). By modifying the surface of the Au@TNA@MB NPs with the ligand folate acid (FA) using NH2-PEG-NH2 as a linker, we demonstrated that the targeted delivery strategy achieved a high accumulation of PSs in cancer cells. The cell viability of T24 cells decreased to 87.1%, 57.1%, and 26.6% upon treatment with 10 ppm[Au] Au@TNA/MB NPs after 45 min, 2 h, and 4 h of incubation, respectively. We also applied the same targeted PDT treatment to normal urothelial SV-HUC-1 cells and observed minor phototoxicity, indicating that this safe photomedicine shows promise for applications aiming to achieve the local depletion of cancer sites without side effects.

Management of High-grade T1 Urothelial Carcinoma

PURPOSE OF REVIEW

The optimal management of high-grade T1 (HGT1) urothelial carcinoma (UC) is complex given its high rate of recurrence, progression, and cancer-specific mortality as well as its clinical variability. Our current treatment paradigm has been supplemented by recent data describing the expanding options for salvage intravesical therapy, bladder preservation, and the promising role of molecular epidemiology. In the current review, we attempt to summarize and critically analyze these studies.

RECENT FINDINGS

Evidence describing new intravesical therapies has demonstrated an adequate safety profile and some efficacy in BCG-unresponsive patients who desire bladder preservation. However, response rates are still poor in this high-risk patient population, and it is important to keep these data in perspective when counseling patients. Concomitantly, the continued molecular characterization of non-muscle-invasive bladder cancer may suggest potential therapeutic targets as well as predictors of treatment response in the future. The integration of new intravesical therapies and molecular data into the current treatment paradigm for HGT1 urothelial carcinoma will be critical to improving oncologic outcomes in this particularly high-risk population.

Subcellular location and photodynamic therapeutic effect of chlorin e6 in the human tongue squamous cell cancer Tca8113 cell line

The present study aimed to investigate the distribution and photodynamic therapeutic effect of chlorin e6 (Ce6) in the human tongue squamous cell carcinoma Tca8113 cell line in vitro. The distribution of Ce6 in the Tca8113 cells was observed in situ combined with mitochondrial and lysosomal fluorescent probes. Next, 630-nm semiconductor laser irradiation was performed. The MTS colorimetric method was used to determine cell survival. Annexin V fluorescein isothiocyanate/propidium iodide (PI) double staining was used to detect early apoptosis following photodynamic therapy (PDT). The flow cytometer was used to analyze the DNA content subsequent to PI-staining. It was observed that Ce6 could combine with the cellular membrane following 30 min of incubation with the Tca8113 cells. As the length of incubation increased, Ce6 gradually entered the cells in a particular distribution and reached saturation by 3 h. Co-localization analysis demonstrated that Ce6 was more likely to be present in the mitochondria than in the lysosomes. The cells incubated with 5 μg/ml Ce6 for 24 h exhibited a low toxicity of 5%, however, following light irradiation, Ce6-PDT was able to kill the Tca8113 cells in vitro. The cell toxicity was positively correlated with Ce6 concentration and light dose, therefore, the effect of Ce6 was concentration/dose-dependent (P<0.01). The lower Ce6 concentrations and light doses could significantly induce apoptosis in the Tca8113 cells, while higher doses increased necrosis/percentage of dead cells. In summary, Ce6 saturated the Tca8113 cells following 3 h of incubation. Furthermore, Ce6-PDT effectively killed the cultured Tca8113 cells in vitro at a safe concentration. At a low concentration and light dose, Ce6 is more likely to induce cell apoptosis via the mitochondria than the lysosomes.

Thiothymidine combined with UVA as a potential novel therapy for bladder cancer

BACKGROUND

Thiothymidine (S(4)TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S(4)TdR and UVA could be an effective treatment for bladder cancer.

METHODS

Uptake and incorporation of S(4)TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S(4)TdR and UVA was investigated in an orthotopic model of bladder cancer in rats.

RESULTS

Thiothymidine (200 μM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S(4)TdR (10-200 μM) and UVA (1-5 kJ m(-2)) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S(4)TdR into DNA (up to 20-fold at IC(5)) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S(4)TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated.

CONCLUSION

These data indicate that the combination of S(4)TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components.

In vitro Antiproliferative Activity of Psoralenes and Mytomicyn C on Reconstituted Bladder Mucosa

In this study, we used a new experimental model, proposed by our group, based on in vitro reconstitution of the human neo-bladder to improve pharmacological studies targeted at optimizing endocavity therapy of superficial bladder cancer. In the light of this, we evaluated the antiproliferative activity on neoplastic and normal origin human urothelium of two psoralen derivatives, 4-methyl-11-dimethilaminopropoxy-benzopsoralen (G50-E) and 8-methoxypsoralen (8-MOP), which are photosensitized by UVA radiation (photochemotherapy PUVA). The pharmacological treatment effects were evaluated by cytotoxic assay based on intramitochondrial capture of MTT, and by using scanning electron microscopy (SEM). Moreover, the cytotoxic effects exerted by the two psoralen derivatives on the neo-bladders were compared to those of mytomicin C, a reference drug for the treatment and prophylaxis of superficial carcinoma bladder relapse. Qualitatively, these investigations confirmed the cytotoxic activity of both psoralen derivatives tested, but, nevertheless, they did not allow a quantitative evaluation of cellular damage.

Endocavitary Therapy of Superficial Cancer Bladder: Evaluation of Photobiological Activity of Psoralen Derivatives on in Vitro Reconstituted Bladder Mucosa

The development of high selectivity drugs for urothelial neoplasia is one of the goals in endocavitary therapy of superficial cancer bladder improvement. Photochemotherapy could cover an important role, because it enables to selectively treat the neoplastic lesions thanks to compounds sensitised by light sources specifically addressed. Aims of this study was to evaluate the in vitro biological activity on normal and neoplastic urothelium of a psoralen derivative, 4-Methyl-11-dimethilaminopropoxy-benzopsoralen (G50-E), against 8-methoxypsoralen (8-MOP) reference drug. Both of them are photosensitied by UVA radiations (photochemotherapy PUVA). An experimental model, which reproduces, even if in a simplified manner, the human bladder mucosa and submucosa organization, was in this study adopted. Firstly, we evaluated the antiproliferative activity of these psoralen derivatives on neoplastic and normal origin human urothelial cell lines. For this we determined the relative IC50 by means of cytotoxic test on cellular monolayer with Trypan Blue. In a second phase of this study, we took advantage from reconstitution technique of bladder mucosa proposed by Fujiyama and previously optimized by our group to evaluate on a three-dimensional model the IC50 effects due to both considered compound. Pharmacologically treated neo-bladder and the control ones were evaluated by means of scanning electron microscopy (SEM) observations. The meaningful result appeared in cellular monolayer experimentation was the selectivity exhibited by both tested compounds (particularly G50-E) against the neoplastic origin urothelial cells. Moreover, scanning electron microscopy investigation, carried on neo-bladder, confirmed the G50-E cytotoxic effect. Therefore, these results suggested the benefit of PUVA therapy for superficial bladder cancer. But, we have to remind that the microscopic observations are just a initial approach and further researches are necessary to quantify the functional and sub-microscopic damage on three-dimensional models.

Photodynamic Therapy for Refractory Superficial Bladder Cancer: Long-Term Clinical Outcomes of Single Treatment Using Intravesical Diffusion Medium

BACKGROUND

Diffuse superficial transitional-cell carcinoma (TCC) refractory to standard therapies poses a clinical dilemma. Photodynamic therapy (PDT), which uses an interaction between absorbed light and a retained photosensitizing agent to destroy tissue, has been used to treat diffuse superficial bladder TCC, although there are few reports of long-term outcomes.

PATIENTS AND METHODS

A series of 34 patients, 29 with TCC carcinoma in situ (CIS) and 5 with multiple small papillary stage T(a) or T(1) lesions, received porfimer sodium (P) 48 hours before whole-bladder PDT with 630-nm laser light. A 0.02% soybean emulsion diffusion medium was instilled into the bladder, and the laser optical fiber was positioned under triplanar sonography prior to PDT. The mean follow-up was 52 months.

RESULTS

At 3 months, a complete response (CR) in 14 (44%) of the 32 evaluable patients, a partial response (PR) in 4 (12%), and no response (NR) in 14 (44%). Four of the five patients with extensive papillary lesions did not respond. The NR rate for patients with CIS with or without resected papillary lesions was 37%. The mean time to recurrence in the CR group was 9.8 months, and five members of this group (36%) underwent cystectomy (mean time 20 months) for persistent/progressive disease (N = 3) or bladder contracture (N = 2). In the NR group, 6 (43%) underwent cystectomy (mean time 14 months) for persistent/progressive disease. Metastatic bladder cancer was the cause of death in only 4 of the 12 patients who have died. Of the remaining 22 patients, 15 are still alive and have an intact bladder, nine with no disease and six with only superficial disease.

CONCLUSION

This is the first report of long-term results following whole-bladder PDT using diffusion medium for isotropic light distribution. More than half of the patients with TCC refractory to traditional intravesical therapy received benefit from a single PDT session. Patients with extensive flat papillary lesions do not appear to respond well. Patients who achieve a CR have less likelihood of and longer time interval before needing cystectomy for progressive disease than NR patients. Our PDT protocol is associated with minimal morbidity in these high-risk patients.

Whole bladder photodynamic therapy with 5-aminolevulinic acid using a white light source

OBJECTIVES

To determine whether whole bladder photodynamic therapy after intravesical administration of 5-aminolevulinic acid using a white light source would destroy urothelial carcinoma. We sought to define the optimal target group of patients for this therapy. The side effects of treatment were also assessed.

METHODS

We performed whole bladder photodynamic therapy with 100 J/cm(2) white light 2 to 4.5 hours after intravesical administration of 17% 5-aminolevulinic acid in 12 patients with recurring, multifocal, Stage pTa, grade I to III, urothelial tumors of the bladder and carcinoma in situ.

RESULTS

Immediately after whole bladder irradiation, histologic examination of biopsies taken from flat suspicious lesions showed no viable cells; remnants of malignant cells were found in papillary tumors. Of the 12 patients, 11 returned for follow-up examination. At a median follow-up of 18 months (range 3 to 25), 3 of the 7 patients with carcinoma in situ and 2 of the 4 patients with papillary tumors were free of disease. In all patients, urinary frequency and urgency subsided within 3 weeks. No decreased bladder capacity or systemic side effects were observed.

CONCLUSIONS

Our preliminary data show that whole bladder photodynamic therapy with intravesically applied 5-aminolevulinic acid using a white light source is effective in destroying flat malignant lesions of the bladder such as carcinoma in situ. The procedure is easy to perform and is not associated with any major side effects. The findings warrant long-term and multicenter studies.

Bladder cancer: epidemiology, diagnosis, and management

PURPOSE

The purpose of this article is to present an overview of the epidemiology diagnosis, and management of bladder cancer, with a focus on the early stage of this disease.

OVERVIEW

English-language articles published between 1990 and 2000, as well as selected abstracts published in non-English languages before 1990, were reviewed. Epidemiologic data clearly indicate that bladder cancer is much more common in men, White persons, and the elderly. Cigarette smoking appears to be the most significant environmental risk factor. Screening for the disease is currently not standard in the United States or Canada. Potential tests include urine cytology, hematuria dipstick, and the urinary biomarkers. Diagnosis is made most often on the basis of the findings of cystoscopy, tumor biopsy, and urine cytology. Transurethral resection (TUR) of the tumor is generally the first-line treatment for superficial disease. Cystectomy is the "gold standard" treatment for invasive disease in many countries, although trimodality therapy (TUR, radiation, systemic chemotherapy) has shown promise as a bladder-preserving strategy. Intravesical therapy is effective for preventing disease recurrence, although its role in slowing disease progression is uncertain. Chemotherapy and radiation also can be used with cystectomy to treat or prevent pelvic recurrence of invasive disease or to prolong life in patients with metastatic disease.

CLINICAL IMPLICATIONS

Bladder cancer is a commonly occurring disease. Prevention efforts must focus on the avoidance or cessation of cigarette smoking and on public education relating to known environmental risk factors. Patient and disease factors must be considered in making treatment decisions and determining prognosis. Careful follow-up after treatment is essential. It is hoped that ongoing research on potential tumor markers and tumor-specific therapies ultimately will result in improved clinical outcomes for patients with this malignancy.

Diagnosis and management of superficial bladder cancer

Bladder cancer is the fourth leading cause of cancer in American men, accounting for more than 12,000 deaths annually. It was one of the first malignancies in which carcinogens were recognized as an important factor in its cause. Currently, cigarette smoking is by far the most common cause of bladder cancer, although occupational exposure to arylamines has been implicated in the past. Gross or microscopic hematuria is the most common sign at presentation. Initial radiologic evaluation usually includes the excretory urography (intravenous pyelography), although further evaluation of the renal parenchyma with ultrasound or computed tomography scanning has been advocated by some. These radiologic studies are unable to provide adequate bladder imaging, and thus cystoscopy is required for the diagnosis of bladder cancer. Most bladder cancers present as "superficial" disease, confined to the bladder mucosa or submucosal layer, without muscle invasion. Superficial tumors consist of papillary tumors that are mucosally confined (Ta), papillary or sessile tumors extending into the lamina propria (T1), and carcinoma in situ, which occurs as "flat" mucosal dysplasia, which can be focal, diffuse, or associated with a papillary or sessile tumor. The natural history of these pathologic subtypes differ significantly. Most superficial tumors (60% to 70%) have a propensity for recurrence after transurethral resection. Some (15% to 25%) are at high risk for progression to muscle invasion. Most superficial tumors can be stratified into high- or low-risk groups depending on tumor stage, grade, size, number, and recurrence pattern. It is important to identify those tumors at risk for recurrence or progression so that adjuvant intravesical therapies can be instituted. Many intravesical chemotherapeutic agents have been shown to reduce tumor recurrence when used in conjunction with transurethral tumor resection. Unfortunately, however, none of these agents have proved to be of benefit in preventing disease progression. Most are given intravesically on a weekly basis, although many studies suggest that a single instillation immediately after transurethral resection may be as good as a longer course of therapy. Although all of these drugs have toxicity, they usually are well tolerated. Intravesical bacille Calmette-Guérin (BCG) is an immunotherapeutic agent that when given intravesically is very effective in the treatment of superficial transitional cell carcinoma. Compared with controls, BCG has a 43% advantage in preventing tumor recurrence, a significantly better rate than the 16% to 21% advantage of intravesical chemotherapy. In addition, BCG is particularly effective in the treatment of carcinoma in situ, eradicating it in more than 80% of cases. In contrast to intravesical chemotherapy, BCG has also been shown to decrease the risk of tumor progression. The optimal course of BCG appears to be a 6-week course of weekly instillations, followed by a 3-week course at 3 months in those tumors that do not respond. In high-risk cancers, maintenance BCG administered for 3 weeks every 6 months may be optimal in limiting recurrence and preventing progression. Unfortunately, adverse effects associated with this prolonged therapy may limit its widespread applicability. In those patients at high risk in whom BCG therapy fails, intravesical interferon-alpha with or without BCG may be beneficial in some. Photodynamic therapy has also been used but is limited by its toxicity. In patients who progress or do not respond to intravesical therapies, cystectomy should be considered. With the development of orthotopic lower urinary tract reconstruction to the native urethra, the quality of life impact of radical cystectomy has been lessened.