Antitumor Efficacy of Intravesical BCG, Gemcitabine, Interferon-α and Interleukin-2 as Mono- or Combination-Therapy for Bladder Cancer in an Orthotopic Tumor Model

Objective:

To reduce adverse effects and improve efficacy of intravesical BCG for bladder cancer, alternative treatment options were investigated in an orthotopic rat tumor model.

Methods:

Superficial bladder cancer was established in syngeneic female rat bladders by instillation of AY-27 cells. Animals were randomly assigned to treatment groups including dose escalation of intravesical BCG with or without interferon-α (IFN-α) or interleukin-2 (IL-2); or graded doses of gemcitabine alone; or BCG plus gemcitabine. Treatments were given twice weekly for 3 weeks. Rats in control groups received saline instillations. Treatment response was monitored by animals’ well-being, survival days, tumor growth inhibition, and histological examination at necropsy.

Results:

Rats receiving monotherapy with intravesical BCG, gemcitabine, or IFN-α, attained significantly better survival and tumor reduction compared with control (P = 0.002; 0.001; 0.002, respectively, Log-rank Test). A dose-dependent treatment response was observed in animals with established bladder tumor receiving escalated BCG instillations. Only high-dose BCG significantly improved animal survival. Although high-dose BCG plus gemcitabine or IFN-α did not increase benefit over monotherapies, low-dose BCG plus IL-2 did show improved efficacy (P = 0.01).

Conclusion:

Intravesical monotherapies with gemcitabine and IFN-α were as effective as BCG for treatment of early non-muscle-invasive urothelial bladder cancer in this immune competent rat model. Combining these agents with high-dose BCG did not further increase efficacy. However, combining low-dose BCG with IL-2 enhanced BCG effectiveness.

Pros and cons of radical cystectomy in the treatment of T1G3 bladder cancer

The management of T1G3 (or high-grade T1) bladder cancer poses a challenging clinical dilemma to the urologist. There are good data supporting bladder conservative therapy with repeat transurethral resection and administration of Bacille Calmette-Guérin (BCG) intravesical therapy but this must include maintenance regimens since only maintenance BCG has been shown to decrease tumor recurrence and progression. Concern over worse survival with a delay in definitive therapy has prompted many to recommend immediate cystectomy for T1G3 disease. Ultimately, the decision needs to be individualized and although certain pathologic factors (T1b disease, early recurrence or progression within three months of BCG therapy, lymphovascular invasion and variant histology) are prognostic of progressive disease, no definitive risk factors for tumor progression have been identified.

Hemorrhagic cystitis: A challenge to the urologist

Severe hemorrhagic cystitis often arises from anticancer chemotherapy or radiotherapy for pelvic malignancies. Infectious etiologies are less common causes except in immunocompromised hosts. These cases can be challenging problems for the urologist and a source of substantial morbidity and sometimes mortality for the patients. A variety of modalities of treatment have been described for the management of hemorrhagic cystitis but there is none that is uniformly effective. Some progress has been made in the understanding and management of viral hemorrhagic cystitis. This article reviews the common causes of severe hemorrhagic cystitis and the currently available management options.

Emerging intravesical therapies for management of nonmuscle invasive bladder cancer

Transitional cell carcinoma (TCC) is the second most common urologic malignancy, and 70% of patients present with superficial or nonmuscle invasive bladder cancer (NMIBC). Intravesical bacillus Calmette-Guerin (BCG) is the most effective agent for preventing disease recurrence, and the only therapy able to inhibit disease progression. However, recurrence rates as high as 30% and significant local and systemic toxicity have led to increased interest in alternative intravesical therapies. In patients refractory or intolerant to BCG, BCG-interferon α2b, gemcitabine, and anthracyclines (doxorubicin, epirubicin, valrubicin) have demonstrated durable clinical responses. Phase I trials investigating alternative cytotoxic agents, such as apaziquone, taxanes (docetaxel, paclitaxel), and suramin are reporting promising data. Novel immunomodulating agents have demonstrated promise as efficacious alternatives in patients refractory to BCG. Optimization of existing chemotherapeutic regimens using hyperthermia, photodynamic therapy, magnetically-targeted carriers, and liposomes remains an area of active investigation. Despite enthusiasm for new intravesical agents, radical cystectomy remains the treatment of choice for patients with NMIBC who have failed intravesical therapy and selected patients with naïve T1 tumors and aggressive features. This report provides a comprehensive review of contemporary intravesical therapy for NMIBC and refractory NMIBC, with an emphasis on emerging agents and novel treatment modalities.

Failure to achieve a complete response to induction BCG therapy is associated with increased risk of disease worsening and death in patients with high risk non-muscle invasive bladder cancer

PURPOSE

The Southwest Oncology Group conducted a randomized trial of induction bacillus Calmette-Guérin (BCG) with or without maintenance BCG. In these additional retrospective analyses, our goal was to evaluate the association of a complete response (CR) or remaining with no evidence of disease (NED) vs. no CR during induction therapy with subsequent survival after adjusting for other potential confounders. Among all patients randomized to maintenance treatment, we also wanted to identify combinations of baseline covariates in order to define prognostic groups for subsequent worsening-free survival.

METHODS

Outcome measures of worsening-free and overall survival were assessed using Kaplan Meier estimates and proportional hazards regression models. For the classification and regression tree (CART) analysis, 434 patients randomized to maintenance vs. no therapy with complete covariate information were included.

RESULTS

Of the 593 evaluable patients, 341 were not randomized to maintenance BCG. Patients who achieved a prior complete response during induction BCG had a 5-year survival probability of 77% compared with 62% for patients who did not [hazard ratio (HR) 0.60; 95% confidence interval (CI) 0.44, 0.81; P = 0.0008]. Prior CR retained significance when adjusted for age, gender, prior intravesical chemotherapy, and papillary disease versus CIS (HR = 0.63; 95% CI: 0.46, 0.86; P = 0.003). CART analysis identified 4 prognostic groups. Older patients (> or =62 years old) previously treated with intravesical chemotherapy who failed to achieve a CR had a 5-fold higher risk of a worsening event relative to those who are younger (<67 years old) and achieve a CR (HR = 5.09; 95% CI: 3.37, 7.68; P < 0.0001).

CONCLUSION

Failure to achieve a complete response after induction BCG is associated with a significant risk of a worsening event and death for patients with CIS or Ta or T1 bladder cancer at increased risk of recurrence.