New drugs and new approaches in metastatic bladder cancer

Adjuvant chemotherapy for bladder cancer

Radical cystectomy is a standard treatment for patients with muscle-invasive bladder cancer. The presence of occult micrometastatic disease is responsible for both local and distant failure after radical surgery. Postoperative administration of chemotherapy in bladder cancer patients can theoretically give the same survival advantage demonstrated in patients with breast and colon cancer. Studies evaluating adjuvant chemotherapy in patients with pT3-pT4 and/or pN+ M0 disease have major deficiencies in terms of sample sizes, early stopping of patient entry, statistical analyses, reporting of results and drawing conclusions. A recent meta-analysis including all previously published randomized trials concludes that, currently, there is insufficient evidence to reliably recommend adjuvant chemotherapy. The results of appropriately sized randomized trials are needed before any definitive conclusions can be drawn.

Patient selection for phase II trials

The standard phase II trial design yields disparate results with similar regimens owing, in part, to variable patient populations enrolled, and appears to be a poor indicator of efficacy demonstrable in a phase III trial. While other phase II trial designs attempt to rectify this problem including the randomized phase II trial and randomized discontinuation trial, they demand more resources and a larger number of patients and are not definitive. A paradigm of multicenter straight phase II trials with rigorous attention to patient selection criteria to improve the validity and reproducibility of results is proposed. Such trials may be superior guides to select regimens for further development than trials that are single-center based with favorable populations.

Novel therapeutics in metastatic bladder cancer

BACKGROUND

Albeit transitional cell carcinoma of the urinary bladder is a chemosensitive neoplasm, metastatic disease is related with poor prognosis and short-term survival data.

OBJECTIVE

Cisplatin-based combination chemotherapy is recognised as the golden standard therapy for patients with inoperable locally advanced or metastatic bladder cancer. However, owing to treatment-related toxicities and short-response durations, novel treatment options or agents, with both enhanced efficacy and tolerability, have been sought.

METHODS

Reviewing the current status and addressing the future of novel anticancer therapeutics in metastatic urinary bladder cancer.

RESULTS/CONCLUSION

Non-platinum, single agents, such as gemcitabine and taxanes, as well as multidrug regimens in doublet or triplet chemotherapeutic combinations are regarded as promising alternatives. Dose intensification of conventional regimens, dose-dense sequential administration of new agents, the use of molecular markers for predicting chemosensitivity and the integration of biologically targeted agents to enhance chemotherapeutic efficacy are promising approaches.

Molecular targeting in the treatment of either advanced or metastatic bladder cancer or both according to the signalling pathways

PURPOSE OF REVIEW

An estimated 300,000 new cases of bladder cancer worldwide are diagnosed annually. Although new cytotoxic chemotherapeutic agents for either advanced or metastatic bladder cancer or both are used, no improvement in survival has been observed. Indeed, the 5-year survival rate of metastatic bladder cancer is very low (6%). The target-directed approach is an attractive challenge for treating specific genetic alterations involved in progression and metastasis development. This article aims to describe the new targeted therapies available to cure advanced cancer or metastatic bladder cancer or both according to the signalling pathways potentially involved.

RECENT FINDINGS

The rapidly expanding understanding of the pathogenesis of bladder cancer at the molecular level has led to the identification of signalling pathways involved in this disease and provided molecular targets for new biological agents directed against tumorigenesis and progression. The recent results of clinical trials have not only highlighted the need to select patients who could benefit from such a therapy but also the fact that oncology has completely entered into a new era.

SUMMARY

Toxic chemotherapeutic agents are slowly being supplemented by a new generation of drugs that recognize specific targets in or on cancer cells. Recent technological advances in pharmacogenomics and proteomics have led to an improvement in identifying biomarkers predictive of response and thereby to identify patients who would be more likely to respond to such a therapy. There is a real hope to improve both the efficiency and the tolerability of bladder cancer treatment.

Trastuzumab, Paclitaxel, Carboplatin, and Gemcitabine in Advanced Human Epidermal Growth Factor Receptor-2/neu–Positive Urothelial Carcinoma: Results of a Multicenter Phase II National Cancer Institute Trial

Purpose

We investigated the safety and efficacy (response rates, time to disease progression, survival) of trastuzumab, carboplatin, gemcitabine, and paclitaxel in advanced urothelial carcinoma patients and prospectively evaluated human epidermal growth factor receptor-2 (Her-2/neu) overexpression rates.

Patients and Methods

Advanced urothelial carcinoma patients were screened for Her-2/neu overexpression. Eligibility for therapy required human epidermal growth factor receptor-2 (Her-2/neu) overexpression by immunohistochemistry (IHC), gene amplification and/or elevated serum Her-2/neu, no prior chemotherapy for metastasis, and adequate organ function including a normal cardiac function. Treatment consisted of trastuzumab (T) 4 mg/kg loading dose followed by 2 mg/kg on days 1, 8, and 15; paclitaxel (P) 200 mg/m2 on day 1; carboplatin (C; area under the curve, 5) on day 1; and gemcitabine (G) 800 mg/m2 on days 1 and 8. The primary end point was cardiac toxicity.

Results

Fifty-seven (52.3%) of 109 registered patients were Her-2/neu positive, and 48.6% were positive by IHC. Her-2/neu–positive patients had more metastatic sites and visceral metastasis than did Her-2/neu negative patients. Forty-four of 57 Her-2/neu–positive patients were treated with TPCG. The median number of cycles was six (range, 1 to 12 cycles). The most common grade 3/4 toxicity was myelosuppression. Grade 3 sensory neuropathy occurred in 14% of patients, and 22.7% experienced grade 1 to 3 cardiac toxicity (grade 3, n = 2: one left ventricular dysfunction, one tachycardia). There were two therapy-related deaths. Thirty-one (70%) of 44 patients responded (five complete and 26 partial), and 25 (57%) of 44 were confirmed responses. Median time to progression and survival were 9.3 and 14.1 months, respectively.

Conclusion

We prospectively characterized Her-2/neu status in advanced urothelial carcinoma patients. TPCG is feasible; cardiac toxicity rates were higher than projected, but the majority were grade two or lower. Determining the true contribution of trastuzumab requires a randomized trial.

Chemotherapy for bladder cancer: treatment guidelines for neoadjuvant chemotherapy, bladder preservation, adjuvant chemotherapy, and metastatic cancer

To determine the optimal use of chemotherapy in the neoadjuvant, adjuvant, and metastatic setting in patients with advanced urothelial cell carcinoma, a consensus conference was convened by the World Health Organization (WHO) and the Société Internationale d'Urologie (SIU) to critically review the published literature on chemotherapy for patients with locally advanced bladder cancer. This article reports the development of international guidelines for the treatment of patients with locally advanced bladder cancer with neoadjuvant and adjuvant chemotherapy. Bladder preservation is also discussed, as is chemotherapy for patients with metastatic urothelial cancer. The conference panel consisted of 10 medical oncologists and urologists from 3 continents who are experts in this field and who reviewed the English-language literature through October 2004. Relevant English-language literature was identified with the use of Medline; additional cited works not detected on the initial search regarding neoadjuvant chemotherapy, bladder preservation, adjuvant chemotherapy, and chemotherapy for patients with metastatic urothelial cancer were reviewed. Evidence-based recommendations for diagnosis and management of the disease were made with reference to a 4-point scale. Results of the authors' deliberations are presented as a consensus document. Meta-analysis of randomized trials on cisplatin-containing combination neoadjuvant chemotherapy revealed a 5% difference in favor of neoadjuvant chemotherapy. No randomized trials have yet compared survival with transurethral resection of bladder tumor alone versus cystectomy for the management of patients with muscle-invasive disease. Collaborative international adjuvant chemotherapy trials are needed to assist researchers in assessing the true value of adjuvant chemotherapy. Systemic cisplatin-based combination chemotherapy is the only current modality that has been shown in phase 3 trials to improve survival in responsive patients with advanced urothelial cancer. A panel of international experts has formulated grade A through D recommendations for the management of patients with locally advanced and metastatic urothelial cancer on the basis of level 1 to 3 evidence and the findings of phase 2 trials, prospective randomized clinical trials, and meta-analyses.

Molecular Pathways in Invasive Bladder Cancer: New Insights Into Mechanisms, Progression, and Target Identification

Papillary and invasive cancers of the urinary bladder appear to evolve and progress through distinct molecular pathways. Invasion in bladder cancer forebodes a graver prognosis, and these tumors are generally characterized by alterations in the p53 and retinoblastoma (RB) pathways that normally regulate the cell cycle by interacting with the Ras–mitogen activated protein kinase signal transduction pathway. Tumor angiogenesis further contributes to the neoplastic growth by providing a constant supply of oxygen and nutrients. Distinct epigenetic and genetic events characterize the interplay between the molecules involved in these pathways, thus affording their use as indicators of prognosis. Efforts are now underway to construct molecular panels comprising multiple markers that can serve as more robust predictors of outcome. While clinical trials for targeted chemotherapy for bladder cancer have commenced, novel genetic and pharmacologic agents that can target pathway-specific molecules are currently under development. The next generation of clinical management for urothelial carcinoma will witness the use of multimarker panels for prognostic prediction and combination therapy directed at novel molecular targets for treatment.

State-of-the-art management of metastatic disease at initial presentation or recurrence

Carcinoma of the bladder is the second most prevalent genitourinay malignancy and the fifth most common solid tumor in the USA. On the basis of favorable response rates and survival data, cisplatin-based regimens can be considered the standard treatment for fit patients with metastatic urothelial cancer. Since cisplatin-containing regimens are contraindicated for patients with impaired renal function, gemcitabine plus either paclitaxel or docetaxel may be an effective and well-tolerated treatment option for these patients. Randomized trials are needed to determine the future role of these combinations in the management of advanced transitional cell carcinoma. The optimal regimens for the medically unfit patients and second-line chemotherapy remain undefined. Postchemotherapy surgical resection of residual cancer may result in a disease-free survival in highly selected patients who would otherwise die of the disease. Progresses in the understanding of the molecular biology of bladder cancer and identification of new targeted therapies will undoubtedly provide new opportunities but whether or not this approach to therapy will lead to better results must still be determined.

Feasibilty study of gemcitabine and cisplatin administered every two weeks in patients with advanced urothelial tumors and impaired renal function

OBJECTIVES

Cisplatin-based combination chemotherapy is the mainstay of treatment for advanced bladder cancer. However, full doses of cisplatin cannot be delivered in patients with impaired renal function. Our aim was to prove the feasibility of a gemcitabine and low-dose cisplatin regimen, delivered every two weeks in patients with impaired renal function.

MATERIAL AND METHODS

Patients with locally advanced or metastatic bladder cancer with creatinine clearance between 35-60 ml/min received gemcitabine 2500 mg/m2 and cisplatin 35 mg/m2 on day 1, every 14 days.

RESULTS

Between January 2004 and March 2005, 17 patients were treated. Mean creatinine clearance was 47.8 ml/min (range: 37-59 ml/min). Four patients had previously received chemotherapy with gemcitabine and/ or platinum. Median number of cycles per patient was 5 (1-13). No patient developed renal toxicity or worsening of renal function. Main toxicities were (grade 3/4): Anemia 2/1; leucopenia: 1/2; trombopenia 1/1. There was one toxic death related to metabolic acidosis, secondary to vomiting. Among 16 patients evaluable for response, we observed one complete response, 7 partial responses (ORR: 53.3%; IC 95%: 28.1-78.5%), 6 stabilizations (37.5%) and 2 progressions (12.5%).

CONCLUSIONS

Gemcitabine and low-dose cisplatin is a safe and feasible combination in patients with poor renal function. Response rates seem similar to those previously described with standard schedules of this combination.

Seven year update of an EORTC phase III trial of high-dose intensity M-VAC chemotherapy and G-CSF versus classic M-VAC in advanced urothelial tract tumours

EORTC protocol 30924 is an international randomized trial reporting a 7.3 year update of a 2 weekly regimen of high-dose intensity chemotherapy with M-VAC plus granulocyte colony stimulating factor (HD-M-VAC) compared to classic M-VAC in advanced transitional cell carcinoma (TCC). Two hundred and sixty three untreated patients with bidimensionally measurable TCC were included. In an intention to treat analysis, there were 28 complete responses (CR) (21%) and 55 partial responses (PR) (41%), for an overall response rate (RR) of 64% on the HD-M-VAC arm. On M-VAC, there were 12 CR (9%) and 53 PR (41%), for an overall RR of 50% . The P-value for the difference in CR was 0.009; and for RR, was 0.06. After a median follow-up of 7.3 years, 24.6% are alive on the HD-M-VAC arm vs. 13.2% on the M-VAC arm. Median progression-free survival was better with HD-MVAC (9.5 months) vs. M-VAC (8.1 months). The mortality hazard ratio (HR) was 0.76. The 2-year survival rate for HD-M-VAC was 36.7% vs. 26.2% for M-VAC. At 5 years, the survival rate was 21.8% in the HD-M-VAC vs. 13.5%. Median survival was 15.1 months on HD-MVAC and 14.9 months on M-VAC. There was one death from toxicity in each arm; and more patients died to malignant disease in the M-VAC arm (76%) than in the HD-M-VAC arm (64.9%). With longer follow-up initial results have been confirmed, and shows that HD-M-VAC produces a borderline statistically significant relative reduction in the risk of progression and death compared to M-VAC.

Pro-apoptotic effect of a nitric oxide-donating NSAID, NCX 4040, on bladder carcinoma cells

Nitric oxide-releasing non steroidal anti-inflammatory drugs (NO-NSAIDs) are a promising class of compounds that cause cell cycle perturbations and induce apoptosis in cell lines from different tumors. We investigated the activity of a recently developed NO-NSAID (NCX 4040) in bladder cancer cell lines (HT1376 and MCR). Cells were treated with different drug concentrations for different exposure times. Cytostatic and cytocidal activity was tested by SRB assay and apoptosis was evaluated by TUNEL analysis, ANNEXIN V assay and fluorescence microscopy. To further investigate the cell death-inducing mechanisms of NCX 4040, we analyzed gp-170, caspase expression and mitochondrial membrane potential (Delta Psi) depolarization. NCX 4040 showed a striking cytocidal activity in both cell lines, reaching LC(50) at a 10-microM and 50-microM concentrations in HT1376 and in MCR cells, respectively, after an exposure of only 6 h followed by an 18-h washout. Apoptosis was triggered in up to 90% of cells and was associated with active caspase-3 expression and Delta Psi depolarization in both cell lines after a 6-h exposure. In conclusion, NCX 4040, which probably causes apoptosis via a mitochondrial-dependent mechanism, could prove to be a useful agent for improving bladder cancer treatment.

Integrating basic science and clinical research in bladder cancer: update from the first bladder Specialized Program of Research Excellence (SPORE)

PURPOSE OF REVIEW

To review the progress of the genitourinary SPORE (Specialized Program of Research Excellence) in bladder cancer.

RECENT FINDINGS

The optimal management of bladder cancer depends on the accurate assessment of the biological potential of the disease. Methotrexate, vincristine, adriamycin and cisplatin (M-VAC) chemotherapy has been the standard of therapy for over a decade. However, there has been no improvement in patient survival. Encouraging preclinical data have resulted in the rapid translation of epidermal growth factor receptor antagonists into the clinic. However, phase I and II single-agent clinical trials in head and neck, lung, and colon cancer failed to match the hope generated by laboratory investigations since only a minority of patients seemed to benefit from this approach. Nonetheless, recent data revealed that non-small-cell lung cancer tumors that responded to single-agent Iressa possessed activating epidermal growth factor receptor mutations. These findings have generated refound interest for epidermal growth factor receptor-dependent tumors that are identified by molecular and pharmacodynamic approaches prior to or early in the course of therapy.

SUMMARY

Targeted therapy against epidermal growth factor receptor has become one of the primary focuses of the genitourinary SPORE in bladder cancer. The SPORE grant scheme is designed to encourage rapid development of new and innovative cancer research in areas of high priority, in this case bladder cancer. The SPORE has facilitated the advancement of novel epidermal growth factor receptor-targeted therapy, such as the monoclonal antibody IMC-225 and the tyrosine kinase inhibitor ZD1839 (Iressa), from the laboratory to clinical trials. The integration of these new biological agents in combination with chemotherapy, in order to abrogate the progression of advanced bladder cancer, is the prime directive of our current phase II Iressa/docetaxel trial.

Novel approaches with targeted therapies in bladder cancer. Therapy of bladder cancer by blockade of the epidermal growth factor receptor family

The improved understanding of the molecular biology of urothelial malignancies is helping to define the role of new targets and prognostic indices that can direct the most appropriate choice of treatment for advanced disease. Many human tumors express high levels of growth factors and their receptors that can be used as potential therapeutical targets. Tyrosine-kinase receptors, including many growth factor receptors such the receptors for epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and Her2/neu, have been found overexpressed in urothelial tumors. For many of these growth factor receptors, the degree of expression has been associated with the progression of cancer and a poor prognosis. Among the best studied growth factor receptors are the two members of EGF receptor familiy EGFr (ErbB-1), and Her2/neu (ErbB-2). Several preclinical studies in bladder cancer models, have confirmed that systemic administration of growth factor inhibitors inhibits the growth and metastasis of human transitional cell carcinoma established in the bladder wall of athymic nude mice. Additional studies indicate that therapy with EGFR inhibitors enhances the activity of conventional cytoreductive chemotherapeutic agents, in part by inhibiting tumor cell proliferation, angiogenesis, and inducing apoptosis. Novel targeted therapy hold promise to improve the current results of bladder cancer treatment. Based on the success seen with anti-HER2 monoclonal antibodies (Herceptin) and the promising results with EGFR targeted agents (IMC-C225 Cetuximab, ZD1389 Iressa, OSI-774 Tarceva, GW 57016) in other tumor types, and based on the results obtained in preclinical models, there is a great interest in assessing these agents in patients with bladder cancer. Several trials are now ongoing testing these new agents alone or in combination with chemotherapy in bladder cancer patients. The integration of these newer biologic agents, probably to supplement rather than to supplant chemotherapeutic drugs, should be a primary direction of research with the objective to interfere with multiple aspects of bladder cancer progression. However, the value of integration of biologically targeted agents into combined modality treatment for patients with bladder cancer has still to be proven.