Quality of pathologic response and surgery correlate with survival for patients with completely resected bladder cancer after neoadjuvant chemotherapy

Predictors of Complete Pathologic Response (pT0) to Neoadjuvant Chemotherapy in Muscle-invasive Bladder Carcinoma

No predictors of a complete pathologic response (pT0) to neoadjuvant chemotherapy (NAC) in muscle-invasive bladder carcinoma have been established. We performed a retrospective analysis of 50 patients to identify potential predictors. Our results showed that the presence of additional transitional cell variants on pathologic examination (mixed tumors) predicted against pT0, suggesting the avoidance of NAC and its morbidity in these patients with mixed tumors.

BACKGROUND

Randomized trials have supported the use of cisplatin-based neoadjuvant chemotherapy (NAC) in muscle-invasive bladder carcinoma (MIBC) owing to the survival advantage, which has correlated with downstaging of the cancer to pT0. Only 30% to 40% of patients receiving NAC have attained a pT0 response at cystectomy; the remaining have either residual disease or progression. We aimed to identify the factors that could predict a pT0 response to NAC.

PATIENTS AND METHODS

Of 336 patients who had undergone robotic cystectomy at our institute from May 2007 to March 2014, we identified 50 patients who had undergone NAC for MIBC. We conducted a retrospective study, dividing these 50 patients into 2 groups, those with and without a pT0. Factors, including age, histologic features, hydronephrosis at initial presentation, and chemotherapy type, were examined by both univariate and multivariate logistic regression analysis.

RESULTS

Of the 50 patients, 14 (28%) had pT0 at cystectomy, 20 (40%) had progressive disease, and 16 (32%) had residual disease. The median age was 67.5 years, the median glomerular filtration rate at presentation was 87.5 mL/min, the patients had undergone a median of 3 NAC cycles, and the median time from the end of chemotherapy to surgery was 4 weeks. The odds of a pT0 response for pure urothelial carcinoma (UC) were approximately 11 times greater relative to cancers with transitional cell variant histologic features or mixed tumors (odds ratio 0.09, 95% confidence interval 0.021-0.380; P = .0011), including squamous, glandular differentiation, small cell, micropapillary, sarcomatoid, nested component, lymphoepithelioma-like, and plasmacytoid variants.

CONCLUSION

The presence of pure UC favored a pT0 response to NAC compared with those with variant histologic features or mixed tumors. These potential predictors warrant prospective validation to allow the ideal selection of patients for NAC.

External Validation of Bladder Cancer Predictive Nomograms for Recurrence, Cancer-Free Survival and Overall Survival following Radical Cystectomy

PURPOSE

We externally validated 3 previously published nomograms to predicting recurrence, and cancer specific and overall survival following radical cystectomy and pelvic lymph node dissection for urothelial carcinoma of the bladder.

MATERIALS AND METHODS

Two surgeons from a single institution performed a total of 197 consecutive radical cystectomies and pelvic lymph node dissections for bladder cancer from January 2003 to September 2009. A total of 23 patients were excluded from analysis. Examined parameters were those used in the original nomograms, including patient age, gender, pathological T stage, N stage, tumor grade, presence of carcinoma in situ and lymphovascular invasion, neoadjuvant chemotherapy, adjuvant chemotherapy and adjuvant radiation therapy. Nomogram predictions were compared to actuarial outcomes and predictive accuracy was quantified using measures of discrimination and calibration.

RESULTS

At the time of analysis 34 patients had experienced recurrence, of whom 28 died of disease and 6 were currently alive with disease. Discrimination at 2, 5 and 8 years was 0.776, 0.809 and 0.794 for recurrence, 0.822, 0.840 and 0.849 for cancer specific survival, and 0.812, 0.820 and 0.825, respectively, for overall survival. Calibration plots revealed nomogram overestimation of all 3 end points.

CONCLUSIONS

Nomograms for bladder cancer recurrence, cancer specific survival and overall survival following radical cystectomy and pelvic lymph node dissection performed well in our series with accuracy comparable to that in the original series. The use of nomogram predictions should be further explored in clinical trials to assess the impact on patient care in clinical practice.

Defects in DNA Repair Genes Predict Response to Neoadjuvant Cisplatin-based Chemotherapy in Muscle-invasive Bladder Cancer

BACKGROUND

Cisplatin-based neoadjuvant chemotherapy (NAC) before cystectomy is the standard of care for muscle-invasive bladder cancer (MIBC), with 25-50% of patients expected to achieve a pathologic response. Validated biomarkers predictive of response are currently lacking.

OBJECTIVE

To discover and validate biomarkers predictive of response to NAC for MIBC.

DESIGN, SETTING, AND PARTICIPANTS

Pretreatment MIBC samples prospectively collected from patients treated in two separate clinical trials of cisplatin-based NAC provided the discovery and validation sets. DNA from pretreatment tumor tissue was sequenced for all coding exons of 287 cancer-related genes and was analyzed for base substitutions, indels, copy number alterations, and selected rearrangements in a Clinical Laboratory Improvements Amendments-certified laboratory.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The mean number of variants and variant status for each gene were correlated with response. Variant data from the discovery cohort were used to create a classification tree to discriminate responders from nonresponders. The resulting decision rule was then tested in the independent validation set.

RESULTS AND LIMITATIONS

Patients with a pathologic complete response had more alterations than those with residual tumor in both the discovery (p=0.024) and validation (p=0.018) sets. In the discovery set, alteration in one or more of the three DNA repair genes ATM, RB1, and FANCC predicted pathologic response (p<0.001; 87% sensitivity, 100% specificity) and better overall survival (p=0.007). This test remained predictive for pathologic response in the validation set (p=0.033), with a trend towards better overall survival (p=0.055). These results require further validation in additional sample sets.

CONCLUSIONS

Genomic alterations in the DNA repair-associated genes ATM, RB1, and FANCC predict response and clinical benefit after cisplatin-based chemotherapy for MIBC. The results suggest that defective DNA repair renders tumors sensitive to cisplatin.

PATIENT SUMMARY

Chemotherapy given before bladder removal (cystectomy) improves the chance of cure for some but not all patients with muscle-invasive bladder cancer. We found a set of genetic mutations that when present in tumor tissue predict benefit from neoadjuvant chemotherapy, suggesting that testing before chemotherapy may help in selecting patients for whom this approach is recommended.

Risk based neoadjuvant chemotherapy in muscle invasive bladder cancer

Muscle invasive bladder cancer (MIBC) is an aggressive disease that frequently requires radical cystectomy (RC) to achieve durable cure rates. Surgery is most effective when performed in organ-confined disease, with the best outcomes for those patients with a pT0 result. The goals of neoadjuvant chemotherapy (NC) are to optimize surgical outcomes for a malignancy with limited adjuvant therapies and a lack of effective salvage treatments. Despite level 1 evidence demonstrating a survival benefit, the utilization of NC has been hampered by several issues, including, the inability to predict responders and the perception that NC may delay curative surgery. In this article, we review the current efforts to identify patients that are most likely to derive a benefit from NC, in order to create a risk-adapted paradigm that reserves NC for those who need it.

Circulating Tumor Cells as Potential Biomarkers in Bladder Cancer

PURPOSE

We explored the diagnostic use of circulating tumor cells in patients with neoadjuvant bladder cancer using enumeration and next generation sequencing.

MATERIALS AND METHODS

A total of 20 patients with bladder cancer who were eligible for cisplatin based neoadjuvant chemotherapy were enrolled in an institutional review board approved study. Subjects underwent blood draws at baseline and after 1 cycle of chemotherapy. A total of 11 patients with metastatic bladder cancer and 13 healthy donors were analyzed for comparison. Samples were enriched for circulating tumor cells using the novel IsoFlux™ System microfluidic collection device. Circulating tumor cell counts were analyzed for repeatability and compared with Food and Drug Administration cleared circulating tumor cells. Circulating tumor cells were also analyzed for mutational status using next generation sequencing.

RESULTS

Median circulating tumor cell counts were 13 at baseline and 5 at followup in the neoadjuvant group, 29 in the metastatic group and 2 in the healthy group. The concordance of circulating tumor cell levels, defined as low-fewer than 10, medium-11 to 30 and high-greater than 30, across replicate tubes was 100% in 15 preparations. In matched samples the IsoFlux test showed 10 or more circulating tumor cells in 4 of 9 samples (44%) while CellSearch® showed 0 of 9 (0%). At cystectomy 4 months after baseline all 3 patients (100%) with medium/high circulating tumor cell levels at baseline and followup had unfavorable pathological stage disease (T1-T4 or N+). Next generation sequencing analysis showed somatic variant detection in 4 of 8 patients using a targeted cancer panel. All 8 cases (100%) had a medium/high circulating tumor cell level with a circulating tumor cell fraction of greater than 5% purity.

CONCLUSIONS

This study demonstrates a potential role for circulating tumor cell assays in the management of bladder cancer. The IsoFlux method of circulating tumor cell detection shows increased sensitivity compared with CellSearch. A next generation sequencing assay is presented with sufficient sensitivity to detect genomic alterations in circulating tumor cells.

Perioperative and Maintenance Therapy After First-Line Therapy as Paradigms for Drug Discovery in Urothelial Carcinoma

Perioperative chemotherapy provided to increase the chance of cure for localized disease and maintenance therapy for metastatic disease represent 2 distinct aspects of the urothelial cancer disease treatment spectrum. The ability to access both pre- and postchemotherapy tissue in the neoadjuvant setting provides important opportunities for translational research to test novel therapies and identify predictors of response to therapy. The maintenance setting may be more complex, and study design and endpoints need to be determined on the basis of the candidate drugs' mechanisms of action and toxicity.

Gemcitabine and cisplatin neoadjuvant chemotherapy for muscle-invasive urothelial carcinoma: Predicting response and assessing outcomes

PURPOSE

To evaluate gemcitabine-cisplatin (GC) neoadjuvant cisplatin-based chemotherapy (NAC) for pathologic response (pR) and cancer-specific outcomes following radical cystectomy (RC) for muscle-invasive bladder cancer and identify clinical parameters associated with pR.

MATERIALS AND METHODS

We studied 150 consecutive cases of muscle-invasive bladder cancer that received GC NAC followed by open RC (2000-2013). A cohort of 121 patients treated by RC alone was used for comparison. Pathologic response and cancer-specific survival (CSS) were compared. We created the Johns Hopkins Hospital Dose Index to characterize chemotherapeutic dosing regimens and accurately assess sufficient neoadjuvant dosing regarding patient tolerance.

RESULTS

No significant difference was noted in 5-year CSS between GC NAC (58%) and non-NAC cohorts (61%). The median follow-up was 19.6 months (GC NAC) and 106.5 months (non-NAC). Patients with residual non-muscle-invasive disease after GC NAC exhibit similar 5-year CSS relative to patients with no residual carcinoma (P = 0.99). NAC pR (≤ pT1) demonstrated improved 5-year CSS rates (90.6% vs. 27.1%, P < 0.01) and decreased nodal positivity rates (0% vs. 41.3%, P<0.01) when compared with nonresponders (≥ pT2). Clinicopathologic outcomes were inferior in NAC pathologic nonresponders when compared with the entire RC-only-treated cohort. A lower pathologic nonresponder rate was seen in patients tolerating sufficient dosing of NAC as stratified by the Johns Hopkins Hospital Dose Index (P = 0.049), congruent with the National Comprehensive Cancer Network guidelines. A multivariate classification tree model demonstrated 60 years of age or younger and clinical stage cT2 as significant of NAC response (P< 0.05).

CONCLUSIONS

Pathologic nonresponders fare worse than patients proceeding directly to RC alone do. Multiple predictive models incorporating clinical, histopathologic, and molecular features are currently being developed to identify patients who are most likely to benefit from GC NAC.

Neoadjuvant therapy in muscle-invasive bladder cancer: a model for rational accelerated drug development

Since the advent of cisplatin-based combination therapy in the management of muscle-invasive and advanced bladder cancer, there has been little progress in improving outcomes for patients. Novel therapies beyond cytotoxic chemotherapy are needed. The neoadjuvant paradigm lends to acquiring ample pretreatment and posttreatment tumor tissue as a standard of care, which enables comprehensive biomarker analyses to better understand mechanisms of both response and resistance, which will aid drug development. This article discusses the evolution of neoadjuvant therapy as standard treatment and the role it may serve toward the development of novel therapies.

ERBB2 Mutations Characterize a Subgroup of Muscle-invasive Bladder Cancers with Excellent Response to Neoadjuvant Chemotherapy

A pathologic complete response to neoadjuvant chemotherapy (NAC) containing platinum is a strong prognostic determinant for patients with muscle-invasive bladder cancer (MIBC). Despite comprehensive molecular characterization of bladder cancer, associations of molecular alterations with treatment response are still largely unknown. We selected pathologic complete responders (ypT0N0; n=38) and nonresponders (higher than ypT2; n=33) from a cohort of high-grade MIBC patients treated with NAC. DNA was isolated from prechemotherapy tumor tissue and used for next-generation sequencing of 178 cancer-associated genes (discovery cohort) or targeted sequencing (validation cohort). We found that 9 of 38 complete responders had erb-b2 receptor tyrosine kinase 2 (ERBB2) missense mutations, whereas none of 33 nonresponders had ERBB2 mutations (p=0.003). ERBB2 missense mutations in complete responders were mostly confirmed activating mutations. ERCC2 missense mutations, recently found associated with response to NAC, were more common in complete responders; however, this association did not reach statistical significance in our cohort. We conclude that ERBB2 missense mutations characterize a subgroup of MIBC patients with an excellent response to NAC.

PATIENT SUMMARY

In this report we looked for genetic alterations that can predict the response to neoadjuvant chemotherapy (NAC) in bladder cancer. We found that mutations in the gene ERBB2 are exclusively present in patients responding to NAC.

Future directions and targeted therapies in bladder cancer

There are substantial unmet needs for patients with metastatic urothelial carcinoma (UC). First-line cisplatin-based chemotherapy regimens yield a median survival of 12 to 15 months and long-term survival in 5% to 15%. Salvage systemic therapy yields a median survival of 6 to 8 months. Hence, the discovery of novel therapeutic targets is of paramount importance. Recent molecular analyses have provided insights regarding molecular tumor tissue alterations on multiple platforms. A multidisciplinary effort using innovative clinical trial designs and exploiting preclinical signals of robust activity guided by predictive biomarkers may provide much needed clinical advances in therapy for advanced UC.

The effect of concomitant carcinoma in situ on neoadjuvant chemotherapy for urothelial cell carcinoma of the bladder: inferior pathological outcomes but no effect on survival

PURPOSE

It is generally believed that carcinoma in situ is refractory to chemotherapy but specific data are lacking to validate this. We evaluated the effect of concomitant clinical carcinoma in situ on cancer specific outcomes after neoadjuvant chemotherapy for muscle invasive bladder cancer.

MATERIALS AND METHODS

We performed an institutional review board approved, multi-institutional, retrospective review of the records of patients treated with neoadjuvant chemotherapy followed by radical cystectomy for muscle invasive bladder cancer from 2008 to 2012. Pretreatment clinical variables were collected and patients were stratified by the presence of clinical carcinoma in situ on precystectomy transurethral bladder tumor resection specimens. Pathological outcomes, including the complete response rate (pT0N0Mx) after neoadjuvant chemotherapy, were compared between the 2 groups. Recurrence-free, cancer specific and overall survival was analyzed.

RESULTS

Of 189 patients who met study criteria 56 (29.6%) had concomitant carcinoma in situ. The condition was associated with a significant decrease in the pathological complete response rate (10.7% vs 26.3%, p = 0.02). This difference was significant on univariate and multivariable analysis (OR 0.34, 95% CI 0.13-0.85, p = 0.02 and OR 0.31, 95% CI 0.12-0.81, p = 0.02, respectively). Despite the decreased complete response rate clinical carcinoma in situ was not associated with a difference in recurrence-free, cancer specific or overall survival. Additionally, when down-staging to pathological carcinoma in situ only disease was considered a complete response, there was no significant change in recurrence-free, cancer specific or overall survival.

CONCLUSIONS

Concomitant carcinoma in situ is associated with a decrease in the complete response rate but this does not appear to impact the survival outcome.

Multicenter assessment of neoadjuvant chemotherapy for muscle-invasive bladder cancer

BACKGROUND

The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting.

OBJECTIVE

We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort.

DESIGN, SETTING, AND PARTICIPANTS

Data were collected retrospectively at 19 centers on patients with clinical cT2-4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013.

INTERVENTION

NAC and RC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and ≤pT1N0 stages.

RESULTS AND LIMITATIONS

Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n=602; 64.4%), followed by MVAC (n=183; 19.6%) and other regimens (n=144; 15.4%). The rates of pT0N0 and ≤pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p=0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61-1.34]; p=0.6).

CONCLUSIONS

Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined.

PATIENT SUMMARY

There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer.

The utility of an extensive postchemotherapy staging evaluation in patients receiving neoadjuvant chemotherapy for bladder cancer

OBJECTIVE

To assess the utility of an extensive restaging examination performed after the completion of neoadjuvant chemotherapy (NAC) but before radical cystectomy (RC) in the management of patients with advanced bladder cancer.

METHODS

We studied 62 patients who underwent NAC with the intent of proceeding to consolidative RC. A restaging examination, including endoscopic and bimanual examination, as well as cross-sectional imaging of the abdomen and pelvis, was performed after chemotherapy. The impact of restaging on clinical management was determined. In patients proceeding to RC, the degree of correlation between clinical stage (at diagnosis vs on restaging) and pathologic stage was determined.

RESULTS

Restaging altered the treatment course in 6 patients (9.7%) in whom RC was not performed because of restaging findings. An additional 56 patients (90.3%) proceeded to RC. In these patients, compared with clinical stage at diagnosis, the postchemotherapy clinical stage correlated more strongly with pathologic stage (κ = 0.02 vs 0.17). On multivariate analysis, diagnostic clinical stage was not associated with pathologic stage (P = .85), whereas postchemotherapy clinical stage was strongly predictive of pathologic stage (P <.01).

CONCLUSION

An extensive restaging examination altered treatment strategy in a small, but clinically significant subset of patients treated with NAC for bladder cancer. Furthermore, restaging allowed for more accurate prediction of pathologic stage after RC, thereby improving assessment of patient prognosis. Consideration should be given to incorporating a restaging evaluation into the standard management paradigm for bladder cancer.

Somatic ERCC2 mutations correlate with cisplatin sensitivity in muscle-invasive urothelial carcinoma

Cisplatin-based chemotherapy is the standard of care for patients with muscle-invasive urothelial carcinoma. Pathologic downstaging to pT0/pTis after neoadjuvant cisplatin-based chemotherapy is associated with improved survival, although molecular determinants of cisplatin response are incompletely understood. We performed whole-exome sequencing on pretreatment tumor and germline DNA from 50 patients with muscle-invasive urothelial carcinoma who received neoadjuvant cisplatin-based chemotherapy followed by cystectomy (25 pT0/pTis "responders," 25 pT2+ "nonresponders") to identify somatic mutations that occurred preferentially in responders. ERCC2, a nucleotide excision repair gene, was the only significantly mutated gene enriched in the cisplatin responders compared with nonresponders (q < 0.01). Expression of representative ERCC2 mutants in an ERCC2-deficient cell line failed to rescue cisplatin and UV sensitivity compared with wild-type ERCC2. The lack of normal ERCC2 function may contribute to cisplatin sensitivity in urothelial cancer, and somatic ERCC2 mutation status may inform cisplatin-containing regimen usage in muscle-invasive urothelial carcinoma.

SIGNIFICANCE

Somatic ERCC2 mutations correlate with complete response to cisplatin-based chemosensitivity in muscle-invasive urothelial carcinoma, and clinically identified mutations lead to cisplatin sensitivity in vitro. Nucleotide excision repair pathway defects may drive exceptional response to conventional chemotherapy.

Neoadjuvant dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin with pegfilgrastim support in muscle-invasive urothelial cancer: pathologic, radiologic, and biomarker correlates

PURPOSE

In advanced urothelial cancer, treatment with dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC) results in a high response rate, less toxicity, and few dosing delays. We explored the efficacy and safety of neoadjuvant ddMVAC with pegfilgrastim support in muscle-invasive urothelial cancer (MIUC).

PATIENTS AND METHODS

Patients with cT2-cT4, N0-1, M0 MIUC were enrolled. Four cycles of ddMVAC were administered, followed by radical cystectomy. The primary end point was pathologic response (PaR) defined by pathologic downstaging to ≤ pT1N0M0. The study used Simon's optimal two-stage design to evaluate null and alternative hypotheses of PaR rate of 35% versus 55%. Secondary end points included toxicity, disease-free survival (DFS), radiologic response (RaR), and biomarker correlates, including ERCC1.

RESULTS

Between December 2008 and April 2012, 39 patients (cT2N0, 33%; cT3N0, 18%; cT4N0, 3%; cT2-4N1, 43%; unspecified, 3%) were enrolled. Median follow-up was 2 years. Overall, 49% (80% CI, 38 to 61) achieved PaR of ≤ pT1N0M0, and we concluded this regimen was effective. High-grade (grade ≥ 3) toxicities were observed in 10% of patients, with no neutropenic fevers or treatment-related death. One-year DFS was 89% versus 67% for patients who achieved PaR compared with those who did not (hazard ratio [HR], 2.6; 95% CI, 0.8 to 8.1; P = .08) and 86% versus 62% for patients who achieved RaR compared with those who did not (HR, 4.1; 95% CI, 1.3 to 12.5; P = .009). We found no association between serum tumor markers or ERCC1 expression with response or survival.

CONCLUSION

In patients with MIUC, neoadjuvant ddMVAC was well tolerated and resulted in significant pathologic and radiologic downstaging.

Improving the outcome of patients with muscle invasive urothelial carcinoma of the bladder with neoadjuvant gemcitabine/cisplatin chemotherapy: A single institution experience

INTRODUCTION

Neoadjuvant cisplatin-based chemotherapy prior to radical cystectomy (RC) for muscle invasive urothelial carcinoma of the bladder improves survival. This study was undertaken to determine the rate of neoadjuvant gemcitabine and cisplatin use prior to RC and to assess its effect on the pathologic response rates and cancer-specific survival (CSS) and overall survival (OS).

METHODS

This retrospective chart review examined all patients having a RC between January 1, 2007 and June 30, 2011. We collected patient demographics, pre-treatment clinical stage, type of chemotherapy, post-RC pathologic data and survival data.

RESULTS

A total of 251 RC were performed of which 160 were for stage cT2-T4 urothelial carcinoma of the bladder. Of the 160 patients, 91 (57%) received neoadjuvant gemcitabine and cisplatin (GC) and 69 (43%) went straight to RC. Patients receiving neoadjuvant GC had a greater chance of achieving a pathologically lower stage compared to the untreated population: pT0 at 21% vs. 3%; non-invasive cancer at 37% vs. 10%; and organ-confined cancer at 60% vs. 33% (p < 0.001). Survival correlated with pathological stage: ≤pT3a patients had a median OS and CSS of 48.8 and 51.2 months compared to an OS and a CSS in ≥pT3b patients of 21.8 and 28.1 months, respectively (p < 0.0001).

CONCLUSIONS

Neoadjuvant chemotherapy for urothelial carcinoma of the bladder is more frequently administered at our institution compared to the published literature. We have found that neoadjuvant chemotherapy increases the rate of down-staging, which is associated with a reduced the risk of death from urothelial carcinoma of the bladder.

Emerging drugs for urothelial carcinoma

INTRODUCTION

Advanced urothelial carcinoma is associated with a poor prognosis. In the metastatic setting, the response rate to first-line, cisplatin-containing chemotherapy is high, but survival is poor. Second-line treatment options are limited. Advanced age at diagnosis and the presence of comorbidities often preclude treatment with cisplatin-containing regimens.

AREAS COVERED

This review addresses the current therapy of urothelial carcinoma, the unmet needs in treatment and the status of drug development in this disease. The molecular targets identified and efforts to incorporate targeted agents into therapy will be addressed.

EXPERT OPINION

There have been no major advances in the treatment of urothelial carcinoma in three decades. Despite high response rates in the first-line setting, survival is limited. Major impediments to improved outcomes include poor durability of response to first-line chemotherapy and lack of second-line treatments. Better understanding in tumor biology has identified multiple targets in urothelial carcinoma; however, such discoveries have yet to lead to the incorporation of targeted agents into the routine treatment of urothelial carcinoma. Multiple ongoing clinical trials are investigating the use of targeted agents in urothelial carcinoma. Continued efforts are underway to better understand the molecular drivers of disease and such efforts are likely to identify additional therapeutic targets.

Neoadjuvant paradigm for accelerated drug development: an ideal model in bladder cancer

Neoadjuvant cisplatin-based combination chemotherapy for muscle-invasive bladder cancer (MIBC) has been shown to confer a survival advantage in two randomized clinical trials and a meta-analysis. Despite level 1 evidence supporting its benefit, utilization remains dismal with nearly one-half of patients ineligible for cisplatin-based therapy because of renal dysfunction, impaired performance status, and/or coexisting medical problems. This situation highlights the need for the development of novel therapies for the management of MIBC, a disease with a lethal phenotype. The neoadjuvant paradigm in bladder cancer offers many advantages for accelerated drug development. First, there is a greater likelihood of successful therapy at an earlier disease state that may be characterized by less genomic instability compared with the metastatic setting, with an early readout of activity with results determined in months rather than years. Second, pre- and post-treatment tumor tissue collection in patients with MIBC is performed as the standard of care without the need for research-directed biopsies, allowing for the ability to perform important correlative studies and to monitor tumor response to therapy in "real time." Third, pathological complete response (pT0) predicts for improved outcome in patients with MIBC. Fourth, there is a strong biological rationale with rapidly accumulating evidence for actionable targets in bladder cancer. This review focuses on the neoadjuvant paradigm for accelerated drug development using bladder cancer as the ideal model.

The impact of smoking on pathologic response to neoadjuvant cisplatin-based chemotherapy in patients with muscle-invasive bladder cancer

PURPOSE

Smoking is the primary etiologic risk factor for bladder cancer and has been implicated in mechanisms of chemoresistance. We investigated smoking as a potential predictor for pathologic outcomes after neoadjuvant chemotherapy (NC) and radical cystectomy (RC) for muscle-invasive bladder cancer.

METHODS

We identified 139 patients treated with neoadjuvant cisplatin-based chemotherapy followed by RC for T2-4aN0M0 bladder cancer. Logistic regression was used to evaluate associations between smoking characteristics and pathologic outcomes (pT0, complete response; pT0/pTis/pT1, any response). In a secondary analysis, multivariate Cox regression was used to assess associations between smoking and recurrence-free and cancer-specific survival.

RESULTS

Our cohort consisted of 99 (71 %) males, with a median age of 65 (interquartile range 56, 71). Prevalence of never, former, and current smokers was 25, 45, and 29 %, respectively. In total, 63 patients experienced disease recurrence, 39 died of disease, and 11 died of other causes. There were no statistically significant associations between smoking characteristics and complete (p = 0.5) or any (p = 0.2) pathologic response to NC. Similarly, we did not find any association between smoking characteristics and recurrence (p = 0.6) or cancer-specific survival (p = 0.9).

CONCLUSIONS

In this series, smoking characteristics were not found to be predictive of pathologic response after NC and RC, although this analysis was limited by the small study sample size. However, the harmful effects of smoking warrants continued emphasis on smoking cessation counseling in bladder cancer patients.

Neoadjuvant chemotherapy improves survival rate in advanced urothelial carcinoma

Radical surgery (RS) with adjuvant chemotherapy (AC) or radiotherapy has been conventionally used for patients with advanced urothelial carcinoma (AUC). Recent research has indicated that systemic neoadjuvant chemotherapy (NC) with RS yields better outcomes than RS alone for patients with locally advanced bladder cancer. However, there are no reports indicating whether NC or AC would be beneficial for patients with AUC. The present study compared the survival rate for AUC patients receiving NC or AC. A retrospective analysis was conducted using data for 64 patients with AUC who underwent RS and systemic chemotherapy at our institution between March 2002 and March 2011. Of the 64 patients, 30 received NC before RS and 34 received RS followed by systemic AC. Pathologic stages (p=0.002), grades (p=0.018) and lymphovascular invasion (p=0.047) were significantly lower in the patients who received NC first than in those who received RC first. Furthermore, analysis of the surgical specimens revealed that 26.7% of patients who received NC before RS had complete remission. There were no significant differences in demographic data, surgical complications, and chemotoxicity between the two patient groups. The progression-free survival (PFS) and overall survival (OS) of patients who received initial NC were significantly better than those of patients who received initial RC (p=0.002 and 0.018, respectively). Our results indicate that NC administration before RS significantly improved the PFS and OS of AUC patients, without increasing surgical complications and chemotoxicity. Further prospectively controlled trials need to be conducted to confirm the effectiveness of NC for AUC patients.

Practical use of perioperative chemotherapy for muscle-invasive bladder cancer: summary of session at the Society of Urologic Oncology annual meeting

At the 11th annual meeting of the Society of Urologic Oncology, an expert panel was convened to discuss the practical use of perioperative chemotherapy for muscle-invasive bladder cancer. The discussion was structured as a case-based debate among the panelists. The topics included: neoadjuvant chemotherapy with a focus on T2 disease, pros and cons, survival data, tolerability of cisplatin-based therapy, can we avoid radical cystectomy in complete responders, limitations and alternatives to cisplatin-based therapy, management of 'suboptimal' chemotherapy, residual disease after neoadjuvant chemotherapy, adjuvant chemotherapy, and key aspects of radical cystectomy and lymph-node dissection in multimodal therapy. The presentations were derived from published literature. The panelists agreed that patients with muscle-invasive bladder cancer should be managed with a multidisciplinary team, including urologist and medical oncologist. Cisplatin-based neoadjuvant chemotherapy has demonstrated improved survival and should be incorporated into the management of all eligible patients with muscle-invasive bladder cancer. However, in some centers, neoadjuvant chemotherapy is reserved for patients with >T2 disease or high-risk features. There are no data for the administration of non-cisplatin-based neoadjuvant chemotherapy, such as carboplatin-combinations. Cisplatin-ineligible patients should proceed directly to surgical extirpation with adjuvant cisplatin-based chemotherapy considered based on pathologic findings. However, the data for adjuvant chemotherapy is less compelling. As our refinement of the selection process continues, we may be able to better identify subsets of patients who may be spared chemotherapy, but much work remains to be done in this arena. The current standard for muscle-invasive bladder cancer patients is cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy and pelvic lymph-node dissection.

A phase 2 clinical trial of sequential neoadjuvant chemotherapy with ifosfamide, doxorubicin, and gemcitabine followed by cisplatin, gemcitabine, and ifosfamide in locally advanced urothelial cancer: final results

BACKGROUND

Neoadjuvant chemotherapy improves the survival of patients with high-risk urothelial cancer. However, the lack of curative alternatives to cisplatin-based chemotherapy is limiting for patients with neuropathy or hearing loss. Sequential chemotherapy also has not been well studied in the neoadjuvant setting. The authors explored sequential neoadjuvant ifosfamide-based chemotherapy in a patient cohort at high risk of noncurative cystectomy.

METHODS

Patients with muscle-invasive cancer and lymphovascular invasion, hydronephrosis, clinical T3b and T4a (cT3b-4a) disease (defined as a 3-dimensional mass on examination under anesthetic or invasion into local organs), micropapillary tumors, or upper tract disease received 3 cycles of combined ifosfamide, doxorubicin, and gemcitabine followed by 4 cycles of combined cisplatin, gemcitabine, and ifosfamide. The primary endpoint was downstaging to pT1N0M0 disease or lower.

RESULTS

At a median follow-up of 85.3 months, the 5-year overall survival (OS) and disease-specific survival (DSS) rates for all 65 patients were 63% and 68%, respectively (95% confidence interval: 5-year OS rate, 0.52%-0.76%; 5-year DSS rate, 0.58%-0.81%). Pathologic downstaging to pT1N0 disease or lower occurred in 50% of patients who underwent cystectomy and in 60% of patients who underwent nephroureterectomy and was correlated with the 5-year OS rate (pT1N0 disease or lower, 87%; pT2-pT3aN0 disease, 67%; and pT3b disease or higher or lymph node-negative disease, 27%; P ≤ .001 for pT1 or lower vs pT2 or higher). Variant histology was associated with an inferior 5-year DSS rate (50% vs 83% in pure transitional cell carcinoma; P = .02). The most frequent grade 3 toxicities were infection (38%), febrile neutropenia (22%), and mucositis (18%). There were 3 grade 4 toxicities (myocardial infarction, thrombocytopenia, and vomiting) and 1 grade 5 toxicity in a patient who refused antibiotics for pneumonia.

CONCLUSIONS

Sequential therapy was active and maintained the historic expectation of achieving a cure. The current results strongly reinforced previous experience suggesting that pathologic downstaging to pT1N0 disease or less is a useful surrogate for eventual cure in patients with urothelial cancer.

A systematic review of neoadjuvant and adjuvant chemotherapy for muscle-invasive bladder cancer

CONTEXT

Muscle-invasive bladder cancer (MIBC) is a disease with a pattern of predominantly distant and early recurrences. Neoadjuvant cisplatin-based combination chemotherapy has demonstrated improved outcomes for MIBC.

OBJECTIVE

To review the data supporting perioperative chemotherapy and emerging regimens for MIBC.

EVIDENCE ACQUISITION

Medline databases were searched for original articles published before April 1, 2012, with the search terms bladder cancer, urothelial cancer, radical cystectomy, neoadjuvant chemotherapy, and adjuvant chemotherapy. Proceedings from the last 5 yr of major conferences were also searched. Novel and promising drugs that have reached clinical trial evaluation were included.

EVIDENCE SYNTHESIS

The major findings are addressed in an evidence-based fashion. Prospective trials and important preclinical data were analyzed.

CONCLUSIONS

Cisplatin-based neoadjuvant combination chemotherapy is an established standard, improving overall survival in MIBC. Pathologic complete response appears to be an intermediate surrogate for survival, but this finding requires further validation. Definitive data to support adjuvant chemotherapy do not exist, and there are no data to support perioperative therapy in cisplatin-ineligible patients. Utilization of neoadjuvant cisplatin is low, attributable in part to patient/physician choice and the advanced age of patients, who often have multiple comorbidities including renal and/or cardiac dysfunction. Trials are using the neoadjuvant paradigm to detect incremental pathologic response to chemobiologic regimens and brief neoadjuvant single-agent therapy to screen for the biologic activity of agents.

New directions for biologic targets in urothelial carcinoma

Urothelial carcinoma remains an important oncologic problem with significant morbidity and mortality. This article provides an overview of the current status of treatment of urothelial carcinoma, with an update on current trials and recent American Society of Clinical Oncology abstracts. As an alternative to focusing on the metastatic setting, we take a broad look at drug development to date, as it spans from early disease to advanced disease in the context of emerging molecular data. This approach allows us to show that each stage involves key considerations based on emerging evidence regarding molecular biology, stage-specific novel endpoints, and rational patient selection that may help further trial designs in the future. Key issues, such as neoadjuvant versus adjuvant perioperative chemotherapy, approaches to salvage second-line therapy in the metastatic setting, and treatment of elderly and cisplatin-ineligible patients, are discussed. New paradigms in clinical research, including novel endpoints, upfront rational patient selection, biomarkers, and trial design, are also addressed.

Novel molecular targets for the therapy of urothelial carcinoma

INTRODUCTION

First-line platinum-based combinations are active in locally advanced and metastatic urothelial carcinoma; however, long-term outcomes including disease-specific and overall survival remain suboptimal. In addition, approximately 40 - 50% of patients with advanced urothelial carcinoma have coexisting medical issues that preclude the use of cisplatin-based therapy. Improvements in our understanding of the molecular mechanisms of urothelial tumorigenesis have led to first-generation clinical trials evaluating novel agents targeting molecular pathways. These are particularly relevant in regard to subpopulations. Novel trial designs warrant consideration to accelerate accrual.

AREAS COVERED

In this review, novel molecular targets for the therapy of urothelial carcinoma, as well as recently completed and ongoing clinical trials utilizing novel targeted agents, are discussed. A Medline search with key words, abstracts reported at national conferences on urothelial carcinoma and NCI clinical trial identifiers was used for this review.

EXPERT OPINION

Improved understanding of molecular biology has identified a number of new molecular targets, but there is a seeming absence of one dominant molecular driver for urothelial cancer. An adaptive and biomarker-derived strategy may be warranted. Clinical trials utilizing targeted agents are ongoing and results are awaited.

Pathologic downstaging is a surrogate marker for efficacy and increased survival following neoadjuvant chemotherapy and radical cystectomy for muscle-invasive urothelial bladder cancer

BACKGROUND

Characterising responders to neoadjuvant chemotherapy (NAC) is important to minimise overtreatment and the unnecessary delay of definitive treatment of urothelial urinary bladder cancer.

OBJECTIVE

To assess the effect of NAC on tumour downstaging and overall survival.

DESIGN, SETTING, AND PARTICIPANTS

A total of 449 patients from the randomised prospective Nordic Cystectomy Trials 1 and 2 were analysed retrospectively. Eligible patients were defined as T2-T4aNXM0 preoperatively and pT0-pT4aN0-N+M0 postoperatively. The median follow-up time was 5 yr.

INTERVENTION

The experimental arm consisted of cisplatin-based NAC; the control arm consisted of cystectomy only.

MEASUREMENTS

The primary outcome was tumour downstaging defined as pathologic TNM less than clinical TNM. Different downstaging thresholds were applied: complete downstaging (CD) (pT0N0), noninvasive downstaging (NID) (pT0/pTis/pTaN0), and organ confinement (OC) (≤ pT3aN0). Downstaging rates and nodal status were compared between the study arms using the chi-square test. Secondary outcome was overall survival (OS) stratified by treatment arm, downstaging categories, and clinical stages, analysed by the Kaplan-Meier method. The following covariates were tested as prognostic factors in univariate and multivariate analyses using the Cox regression method: age, sex, clinical stage, pN status, NAC, CD, NID, and OC.

RESULTS AND LIMITATIONS

Downstaging rates increased significantly in the NAC arm independent of the downstaging threshold. The impact was more prominent in clinical T3 tumours, with a near threefold increase in CD tumours. The combination of CD and NAC showed an absolute risk reduction of 31.1% in OS at 5 yr compared with CD controls. The combination of NAC and CD revealed a hazard ratio of 0.32 compared with 1.0 for the combination of no NAC and no CD. Limitations were the retrospective approach and uncertain clinical TNM staging.

CONCLUSIONS

Survival benefits of NAC are reflected in downstaging of the primary tumour. Chemo-induced downstaging might be a potential surrogate marker for OS.

Neoadjuvant gemcitabine and cisplatin chemotherapy for locally advanced urothelial cancer of the bladder

BACKGROUND

The purpose of this study was to investigate the effect of neoadjuvant chemotherapy with gemcitabine and cisplatin (GC) on pathologic down-staging of patients with locally advanced urothelial cancer (UC) of the bladder.

METHODS

This was a retrospective cohort study of patients treated with radical cystectomy (RC) for clinical stage cT2-T4, N any, M0 bladder UC at Strong Memorial Hospital from 1999 to 2009. The primary exposure variable was use of neoadjuvant chemotherapy (GC vs none). The primary outcome was stage pT0 at RC. Secondary outcomes included other down-staging end points in the bladder (<pT1, <pT2, <pT3), nodal status, and surgical margins. Linear probability models were used to estimate the effect of neoadjuvant GC on tumor down-staging with adjustment for clinical staging variables.

RESULTS

A total of 160 eligible patients were identified, of whom 25 were treated with neoadjuvant GC before RC (GC + RC) and 135 without neoadjuvant chemotherapy (RC only). Stage pT0 at cystectomy was found in 20% of patients in the GC + RC group and in 5% of patients in the RC group (adjusted risk difference [aRD] = 16%, P = .03). For other down-staging end points, the estimated treatment effect was as follows (all point estimates favoring chemotherapy): <pT1 aRD = 30% (P = .005); <pT2 aRD = 30% (P = .004); <pT3 aRD = 31% (P = .008); margins aRD = 8% (P = .41); nodes aRD = 4% (P = .74).

CONCLUSIONS

Neoadjuvant GC was found to be capable of down-staging UC in the bladder; however, no effect on disease in nodes was seen in this study.

Neoadjuvant gemcitabine plus cisplatin for muscle-invasive bladder cancer

OBJECTIVE

Downstaging by neoadjuvant chemotherapy improves the survival of patients with muscle-invasive bladder cancer. In salvage setting, gemcitabine plus cisplatin has demonstrated an efficacy similar to that of methotrexate, vinblastine, doxorubicin and cisplatin with less toxicity. Therefore, the application of neoadjuvant gemcitabine plus cisplatin is also being anticipated.

METHODS

Twenty-two patients who received neoadjuvant gemcitabine plus cisplatin were evaluated. The rate of downstaging, chemotherapy delivery profile and toxicity data were assessed. As comparator group, nine patients who were administered with neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin were evaluated.

RESULTS

A mean of 1.9 cycles of neoadjuvant gemcitabine plus cisplatin were performed. Achieved drug intensity for gemcitabine and cisplatin was 83.8 and 95.4%. Downstaging to pT0 and <pT2 was achieved in 50.0 and 63.6%. Grade 3 or 4 neutropenia, anemia, thrombocytopenia and febrile neutropenia appeared in 14.3, 2.4, 21.4 and 2.4%, respectively. Grade 3 or 4 non-hematologic toxicity was not observed. Thrombocytosis developed in 26.2%. A mean of 2.3 cycles of neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin were performed. The achieved drug intensities for methotrexate, vinblastine, doxorubicin and cisplatin were 59.6, 69.8, 100 and 88.6%. In patients treated with neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin, downstaging to pT0 and <pT2 was achieved in 22.2 and 44.4%. Grade 3 or 4 neutropenia, anemia and thrombocytopenia was present in 19.1, 9.5 and 4.8%. Grade 3 nausea developed in 28.6%.

CONCLUSIONS

The rate of downstaging by neoadjuvant gemcitabine plus cisplatin was comparable with that by methotrexate, vinblastine, doxorubicin and cisplatin. Gemcitabine plus cisplatin was associated with less non-hematologic toxicity than methotrexate, vinblastine, doxorubicin and cisplatin.

Maximizing cure for muscle-invasive bladder cancer: integration of surgery and chemotherapy

CONTEXT

The optimal treatment strategy for muscle-invasive bladder cancer remains controversial.

OBJECTIVE

To determine optimal combination of chemotherapy and surgery aimed at preserving survival of patients with locally advanced bladder cancer.

EVIDENCE ACQUISITION

We performed a critical review of the published abstract and presentation literature on combined modality therapy for muscle-invasive bladder cancer. We emphasized articles of the highest scientific level, combining radical cystectomy and perioperative chemotherapy with curative intent to affect overall and disease-specific survival.

EVIDENCE SYNTHESIS

Locally invasive, regional, and occult micrometastases at the time of radical cystectomy lead to both distant and local failure, causing bladder cancer deaths. Neoadjuvant and adjuvant chemotherapy regimens have been evaluated, as well as the quality of cystectomy and pelvic lymph node dissection.

CONCLUSIONS

Prospective, randomized clinical trials argue strongly for neoadjuvant cisplatin-based chemotherapy followed by high-quality cystectomy performed by an experienced surgeon operating in a high-volume center. Adjuvant chemotherapy after surgery is also effective when therapeutic doses can be given in a timely fashion. Both contribute to improved overall survival; however, many patients receive only one or none of these options, and the barriers to receiving optimal, combined, systemic therapy and surgery remain to be defined. An aging, comorbid, and often unfit population increasingly affected by bladder cancer poses significant challenges in management of individual patients.

Prognostic risk stratification of pathological stage T2N0 bladder cancer after radical cystectomy

OBJECTIVE

• To stratify risk of pathological (p) T2N0 urothelial carcinoma of the bladder after radical cystectomy (RC) based on pathological factors to facilitate the development of adjuvant therapy trials for high-risk patients.

PATIENTS AND METHODS

• The study comprised 707 patients from a database of patients with pT2N0 urothelial carcinoma of the bladder who had undergone RC and not received perioperative chemotherapy. • The effect of residual pT-stage at RC, age, grade, lymphovascular invasion and number of lymph nodes removed on recurrence-free survival was evaluated using Cox regression analyses. A weighted prognostic model was devised with significant variables.

RESULTS

• The median follow up was 60.9 months. In multivariable analyses, residual disease at RC (pT2a: hazard ratio (HR) 1.740, P = 0.03; for pT2b: HR 3.075, P < 0.001; both compared with <pT2), high-grade (HR 2.127, P = 0.09) and lymphovascular invasion (HR 2.234, P < 0.001) were associated with recurrence-free survival (c = 0.70). • Three risk groups were devised based on weighted variables with 5-year recurrence-free survival of 95% (95% CI 87-98), 86% (95% CI 81-90) and 62% (95% CI 54-69) in the good-risk, intermediate-risk and poor-risk groups, respectively (c = 0.68). The primary limitation is the retrospective and multicenter feature.

CONCLUSIONS

• A prognostic risk model for patients with pT2N0 bladder cancer undergoing RC with generally adequate lymph node dissection was constructed based on residual pathological stage at RC, grade and lymphovascular invasion. • These data warrant validation and may enable the selection of patients with high-risk pT2N0 urothelial carcinoma of the bladder for adjuvant therapy trials.

Neoadjuvant therapy preceding prostatectomy for prostate cancer: rationale and current trials

Neoadjuvant therapy improves outcomes for a number of malignancies and provides intermediate pathologic outcomes, which correlate with long-term outcomes. Neoadjuvant androgen-deprivation therapy, alone or with docetaxel chemotherapy, preceding prostatectomy for localized prostate cancer is feasible and demonstrates pathologic activity, but evidence for improved long-term outcomes is lacking. Data in support of the further exploration of neoadjuvant therapy for localized prostate cancer preceding prostatectomy are reviewed. Ongoing randomized trials are elucidating the impact of neoadjuvant androgen deprivation combined with docetaxel chemotherapy on pathologic and long-term outcomes. The correlation of pathologic and biologic outcomes with long-term outcomes in this setting is unknown. The neoadjuvant therapy approach followed by prostatectomy is feasible with a wide array of agents and provides a paradigm for evaluating the activity, and mechanism of action and resistance to new treatments. This promising modality may aid the rapid development of novel therapeutic agents. A multidisciplinary approach involving oncologists, urologists and pathologists is critical to the success of this model.