Contemporary Intravesical Treatment Options for Urothelial Carcinoma of the Bladder

CLT1 targets bladder cancer through integrin α5β1 and CLIC3

High-grade non-muscle-invasive bladder cancer is commonly treated with Bacillus Calmette-Guérin, an immunotherapeutic that depends on fibronectin and tumor cell integrin α5β1 for internalization into bladder cancer cells. We previously showed that the anti-angiogenic peptide CLT1 forms cytotoxic complexes with fibronectin that are cooperatively internalized into proliferating endothelium through ligation of integrins and chloride intracellular channel 1. While CLT1 has no effect on mature, differentiated cells, we show here that CLT1 is highly cytotoxic for a panel of bladder tumor cell lines as well as a variety of cell lines derived from kidney, lung, breast, and prostate cancer. Paralleling our previous results, we found CLT1-induced tumor cell death to be increased in the presence of fibronectin, which mediated CLT1 internalization and subsequent autophagic cell death in a mechanism that depends on tumor cell integrin α5β1 and chloride intracellular channel 3 (CLIC3). This mechanistic link was further supported by our results showing upregulation of α5β1 and CLIC3 in CLT1-responsive tumor cell lines and colocalization with CLT1 in tumor tissues. Incubating tumor tissue from patients with bladder cancer with fluorescein-conjugated CLT1 resulted in a strong and specific fluorescence whereas normal bladder tissue remained negative. On the basis of its affinity for bladder tumor tissue and strong antitumor effects, we propose that CLT1 could be useful for targeting bladder cancer.

Efficacy of combined intravesical immunotherapy and chemotherapy for non-muscle invasive bladder cancer

Intravesical immunotherapy using attenuated bacillus Calmette-Guérin (BCG) strains and intravesical chemotherapy are the modalities most commonly used to treat intermediate- or high-risk patients with non-muscle invasive bladder cancer. BCG has been shown to decrease recurrence rates by up to 67% compared with tumor resection alone, but intensive BCG maintenance regimens are poorly tolerated in a large proportion of patients. Intravesical chemotherapy also decreases the risk of recurrence for these patients, but has diminished efficacy compared with BCG. If BCG dose reduction can be achieved with combined intravesical immunotherapy and chemotherapy, this regimen may improve compliance and thus optimize treatment for these patients by limiting side effects from BCG monotherapy, while at the same time improving oncologic efficacy via the separate anti-tumor mechanisms of these agents. The authors discuss the most recent data regarding combining these agents in an alternating or sequential regimen.

Intravesical Bacillus Calmette-Guérin versus epirubicin for Ta and T1 bladder cancer

BACKGROUND

Bladder cancer accounts for approximately 4.4% of adult malignancies, and approximately 80% of bladder cancer presents initially as transitional cell carcinoma that is confined to the urothelium (stage Ta) or lamina propria (stage T1). Intravesical administration of Bacillus Calmette-Guérin (BCG) and epirubicin (EPI) has been proven to reduce tumour recurrence and prevent or delay progression to muscle invasion and metastases. However, comparison of the effectiveness and safety of intravesical BCG and EPI in bladder cancer has yet to be explored.

OBJECTIVES

To compare the effectiveness and safety of BCG with EPI in the treatment of Ta and T1 bladder cancer.

SEARCH STRATEGY

A comprehensive search of MEDLINE (1966 to April 2010), EMBASE (1980 to April 2010), Health Services Technology, Administration, and Research (HealthSTAR), the Cochrane Central Register of Controlled Trials (CENTRAL), CancerLit, and Database of Abstracts of Reviews of Effectiveness (DARE), was performed, and handsearching of relevant journals was undertaken.

SELECTION CRITERIA

All randomised or quasi-randomised trials (in which allocation was obtained by alternation - e.g., alternate medical records, date of birth, or other predictable methods) in patients with Ta or T1 bladder cancer that compared intravesical BCG with EPI were included. No language restrictions were applied.

DATA COLLECTION AND ANALYSIS

Trial eligibility, methodological quality and data extraction were assessed independently by two reviewers. We compared dichotomous outcomes (frequency of tumour recurrence, progressive disease by stage, mortality, distant metastases, local and systemic adverse effects, treatment delayed or stopped due to adverse effects) using risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Five trials of 1111 participants were included in this review. For BCG, 549 patients were treated, and 562 with EPI. Of the evaluated patients, 35.5% (195/549) in the BCG group and 51.4% (289/562) in the EPI group had tumour recurrence (P < 0.05). For disease progression (BCG, 44/549; EPI, 58/562) and distant metastases (BCG, 23/487; EPI, 31/495), there were no significant differences (P = 0.19 and P = 0.29, respectively). Only two trials, including 769 patients, had sufficient data for us to analyze disease-specific (BCG, 22/383; EPI, 26/386) and overall mortality (BCG, 125/383; EPI, 147/386). Neither comparison was significant (P = 0.93 and P = 0.12, respectively). In four studies reporting toxicity, BCG was associated with significantly more drug-induced cystitis [BCG, 54.1% (232/429); EPI, 31.7% (140/441)] and haematuria [BCG, 30.8% (132/429); EPI, 16.1% (71/440)]. Similarly, in three studies reporting systemic toxicity, BCG had significantly higher toxicity than the EPI (34.8% (134/385) versus 1.3% (5/393), respectively). In a meta-analysis comparing 'treatment delayed or stopped' (BCG, 40/431; EPI, 33/441), there was no significant difference between BCG and EPI treatments (P = 0.82).

AUTHORS' CONCLUSIONS

The data from the present meta-analysis indicate that intravesical BCG treatment is more efficacious than EPI in reducing tumour recurrence for Ta and T1 bladder cancer. However, BCG appears to be associated with a higher incidence of adverse effects, such as drug-induced cystitis, haematuria and systemic toxicity, than EPI. The overall quality of the evidence is rather low. Well-designed, high quality randomised controlled trials with good allocation concealment are required.

Multi-organ failure with atypical liver granulomas following intravesical Bacillus Calmette-Guerin instillation

Bacillus Calmette-Guerin (BCG) intravesical instillation has been adopted in the treatment of patients with superficial bladder cancer. BCG-induced disseminated infection, though rare, has been associated with the histological finding of epithelioid granulomas in different organs, including the liver. We report the case of an adult patient with multi-organ failure, who developed sepsis, acute respiratory failure and acute hepatic failure with encephalopathy whose liver biopsy confirmed the presence of atypical, granulomatous-like lesions. Recovery was observed only after empirical therapy for Mycobacterium bovis with isoniazid, rifampicin, ethambutol and steroids was introduced. This case highlights the importance of a thorough patient assessment in order to exclude other more common causes of hepatic granulomas and to confirm diagnosis. Histological findings may be non-specific when the liver is involved in BCG-induced disseminated infection.

Intravesical mycobacterial cell wall-DNA complex in the treatment of carcinoma in situ of the bladder after standard intravesical therapy has failed

PURPOSE

We assessed the clinical efficacy and safety of mycobacterial cell wall-DNA complex after intravesical administration in patients with carcinoma in situ in whom prior therapy with bacillus Calmette-Guerin failed or in those who were treatment naïve.

MATERIALS AND METHODS

Patients received 6 weekly instillations of 4 or 8 mg mycobacterial cell wall-DNA complex (formulated as an emulsion) followed by 3 weekly instillations at weeks 12 and 24. Efficacy and safety were evaluated throughout the treatment phase and at months 12 and 18.

RESULTS

A total of 55 patients (mean age 74 years, 74.6% male) received 4 mg (25) or 8 mg (30) mycobacterial cell wall-DNA complex emulsion. All patients were previously treated with bacillus Calmette-Guerin except for 8 who were treatment naïve and 2 who received chemotherapy. In the intent to treat population the complete response rate was 27.3% at weeks 12 and 26 in the 4 mg group while 46.4% of patients receiving 8 mg had a complete response at both points. Mycobacterial cell wall-DNA complex was well tolerated by both dose groups. Overall 90% of all adverse events were mild to moderate in severity.

CONCLUSIONS

Mycobacterial cell wall-DNA complex has shown antineoplastic activity in patients with bladder cancer with less toxicity than that associated with bacillus Calmette-Guerin administration. The tolerance and efficacy of mycobacterial cell wall-DNA complex might hold promise for the treatment of carcinoma in situ of the bladder.

Telomerase targeted oligonucleotide thio-phosphoramidates in T24-luc bladder cancer cells

Bladder carcinoma is the second most common genitourinary malignancy. Treatment options for bladder cancer include surgery, combined with chemotherapy, radiation, and/or immunotherapy. The adjuvant chemotherapy and immunotherapy regimen have been widely used in locally invasive as well as metastatic disease. The evaluation of new active agents with improved tolerability has been the focus of investigations over the past decade with minimal overall improvements in outcomes. Telomerase activity has been found in approximately 85-90% of all human tumors, but not in the majority of adjacent normal tissues. This suggests that telomerase may be an attractive target for the development of novel anticancer therapeutic agents. GRN163L is a lipid conjugated oligonucleotide N3' --> P5' thio-phosphoramidate, and is a potent telomerase RNA (hTR) template antagonist. In the present study, we show that the telomerase activity of T24-luc bladder cancer cells is inhibited by 1 microM GRN163L within 24 h of incubation. After two weeks of exposure to GRN163L, T24-luc cells became "clustered" whereas non-cancerous normal human uroepithelial cells were not morphologically affected. Moreover, in vitro GRN163L treated T24-luc bladder cancer cells entered G(0)/G(1) arrest following 2 weeks of continuous exposure and stopped dividing. Mismatch control compound had no effect on normal bladder epithelial cells or T24-luc cells. Additionally, a new generation of thio-phosphoramidate oligonucleotides were designed and tested in T24-luc cells and compared with GRN163L. The obtained results warrant further in vivo evaluation of GRN163L as a potential treatment for bladder cancer.

[Precancerous lesions of the urothelium. From Feulgen staining to single cell CGH]

Feulgen staining represents a staining method to quantitatively document the DNA content of a nucleus. Thus it is an excellent and straightforward method to reflect the irregular increase in DNA content of a malignant cell as a sign of genetic instability. Genetic instability of the tumour cell is the key feature of the 2004 WHO classification of bladder tumours, in which flat and papillary neoplasia are grouped into low- and high-grade lesions. "High grade" represents the tumor with genetic instability and consequently a higher likelihood of progression. Concomitant distinct genetic aberrations other than the numeric ones are increasingly identified as discriminators and help group the entities. The current status of genetic investigations, especially those in precancerous lesions, will be outlined in this review in the context of morphology (histology and cytology) as well as clinical situation.