Sarcopenia Predicts Disease Progression in Patients with T1 High-grade Non–muscle-invasive Bladder Cancer Treated with Adjuvant Intravesical Bacillus Calmette-Guérin: Implications for Decision-making?

Background

Skeletal muscle loss (sarcopenia) has been linked to cancer cachexia and can predict survival in several tumors, including advanced genitourinary malignancies.

Objective

To investigate the predictive and prognostic role of sarcopenia in patients with T1 high grade (HG) non-muscle invasive bladder cancer (NMIBC) treated with adjuvant intravesical Bacillus Calmette-Guerin (BCG).

Design setting and participants

Oncological outcomes were evaluated for 185 patients with T1 HG NMIBC treated with BCG at two European referral centers. Sarcopenia, identified from computed tomography scans performed within 2 mo after surgery, was defined as a skeletal muscle index of <39 cm²/m² for women and <55 cm²/m² for men.

Outcome measurements and statistical analysis

The main endpoint was the association between sarcopenia and disease recurrence and progression. Kaplan-Meier curves and multivariable Cox models were built, and the clinical value of any association was assessed using Harrell's C index and decision curve analysis (DCA).

Results and limitations

Sarcopenia was present in 130 patients (70%). On multivariable Cox regression analyses that accounted for the effect of standard clinicopathological prognosticators, sarcopenia was independently associated with disease progression (hazard ratio 3.41; p = 0.02). Addition of sarcopenia to a standard model for prediction of disease progression improved the discrimination of the model from 62% to 70%. DCA revealed superior net benefits for the proposed model in comparison to the strategies of treating all or no patients with radical cystectomy, and in comparison to the existing predictive model. Limitations are inherent to the retrospective design.

Conclusions

We demonstrated the prognostic role of sarcopenia in T1 HG NMIBC. Pending external validation, this tool could be easily incorporated into existing nomograms for prediction of disease progression to improve clinical decision-making and patient counseling.

Patient summary

We looked at the role of loss of skeletal muscle (sarcopenia) as a factor in predicting prognosis for stage T1 high-grade non-muscle-invasive bladder cancer. We found that sarcopenia is a ready-to-use, cost-free marker that could be used to guide treatment and follow-up in this disease, although the results need to be confirmed in other studies.

Update on systemic treatment of upper tract urothelial carcinoma: a narrative review of the literature

Urothelial cancer (UC) is most commonly found in the urinary bladder, but can also appear in the upper urinary tract, where it is associated with several disease-specific challenges affecting its diagnosis, clinical staging, surgical management, and systemic therapy. A significant number of patients experience extra-vesical disease recurrence despite radical nephroureterectomy (RNU), leading to inevitable demise. Over the last years, the therapeutic armamentarium of UC has expanded with several systemic treatment options entering clinical care and deliver the potential to support a more individualized treatment in the near future. Currently, novel targeted therapies are emerging, accompanied with extensive biomarker research, which leads to a better understanding of the disease and therefore, reshaping the treatment landscape continuously and decisively. Though, systemic treatment of UTUC comes along with certain challenges that are specific to the disease, e.g., loss of renal function after RNU, which might result in ineligibility for a cisplatin-based chemotherapy. In this narrative review, the current standard of systemic treatment of UC in the perioperative and metastatic treatment setting are reported, with focus on UTUC. In addition, molecular aspects of UTUC, as well as future directions and specific implications for treatment of patients diagnosed with UTUC are discussed.

The Predictive Value of Programmed Death Ligand 1 in Patients with Metastatic Renal Cell Carcinoma Treated with Immune-checkpoint Inhibitors: A Systematic Review and Meta-analysis

CONTEXT

Immune-checkpoint inhibitors (ICIs) are a mainstay treatment of metastatic renal cell carcinoma (mRCC). As not all patients benefit from ICIs, a biomarker-driven clinical decision-making strategy is desirable.

OBJECTIVE

To assess the predictive value of programmed death ligand 1 (PD-L1) in mRCC patients treated with ICIs.

EVIDENCE ACQUISITION

Multiple databases were searched for articles published up to April 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Studies comparing objective response rate (ORR), complete response rate (CRR), progressive disease rate (PDR), or progression-free survival (PFS) based on tumor PD-L1 status in mRCC patients were eligible.

EVIDENCE SYNTHESIS

Six studies matched our eligibility criteria. Treatment with ICIs was associated with significantly higher ORRs and CRRs, and lower PDRs in patients with PD-L1-positive tumors than in those with PD-L1-negative status (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.48-2.28; OR 3.11, 95% CI 2.04-4.75; and OR 0.43, 95% CI 0.31-0.60, respectively). ICI treatment was associated with significantly better PFS in PD-L1-positive patients than in sunitinib-treated patients (hazard ratio 0.65, 95% CI 0.57-0.74), whereas this was not found in patients with PD-L1-negative tumors. Compared with sunitinib, ICI combination therapy improved ORRs and PFS significantly in PD-L1-positive patients of all examined ICIs. Nivolumab plus ipilimumab had the highest likelihood of providing the highest ORR and longest PFS in PD-L1-positive patients.

CONCLUSIONS

PD-L1 positivity of the tumor is associated with improved ORRs and prolonged PFS in mRCC patients receiving ICI treatment and thus helps identify mRCC patients most likely to benefit from ICI treatment.

PATIENT SUMMARY

The use of an immune-checkpoint inhibitor for the treatment of metastatic renal cell carcinoma (mRCC) improved oncological outcomes, and the status of programmed death ligand 1 could contribute to guiding patients and clinicians when determining personalized treatment strategies for mRCC.

Trend analysis and regional tumor incidence in Germany for testicular cancer between 2003 and 2014

BACKGROUND

Testicular germ cell tumor (TGCT) is one the most common solid tumors in men between the age of 15 and 35 with an overall incidence rate of 1-1.5 %. Epidemiologic studies have demonstrated different incidence patterns in western civilized countries with overall rising incidence trends.

OBJECTIVE

To analyze differences in regional tumor incidence rates for TGCT and perform a trend analysis for TGCT between 2003 and 2014 in Germany.

MATERIAL AND METHODS

TGCT cases in Germany which were diagnosed between 2003 and 2014 were provided by the Robert-Koch-Institute, Berlin. For statistical analysis, cluster and spatial scan tests according to Kulldorff were used for cases with seminoma and non-seminoma. Results are presented in administrative districts and graphically illustrated. We performed a trend-analysis in order to evaluate age-adjusted incidence trends in Germany. Tests were two-sided with a level of significance of α=0.05.

RESULTS

In total we included 35,066 patients. Overall, 22,634 cases had newly diagnosed seminoma and 12,432 were diagnosed as non-seminoma. Maximum incidence of seminoma and non-seminoma was observed for age-group 38-40 years and 26-28 years, respectively. No second peak for the incidences of seminoma and non-seminoma with respect to age were observed. Cluster analysis revealed areas with high and low incidence rates as well as slightly different spatial distribution in Germany between seminoma and nonseminoma. Furthermore, there was no significant increase in age-adjusted incidence rates over the reviewed time period in both cohorts.

DISCUSSION

In this study differences in reginal tumor incidence rates for seminoma and non-seminoma are reported with both tumor entities revealing distinct clusters. Furthermore, tumor incidence trends for seminoma and nonseminoma between 2003 and 2014 were stable which might indicate the beginning of a plateau phase for TGCT incidence rates in Germany.

CONCLUSION

In this analysis we were able to identify regions with significantly higher tumor incidence rates for both seminoma and non-seminoma which were specific for these two subtypes. Furthermore, trend analysis revealed a steady incidence rate for testicular cancer in Germany.

Diagnostic accuracy, clinical utility and influence on decision-making of a methylation urine biomarker test in the surveillance of non-muscle-invasive bladder cancer

Objectives

To investigate prospectively the clinical utility and influence on decision‐making of Bladder EpiCheck™, a non‐invasive urine test, in the surveillance of non‐muscle‐invasive bladder cancer (NMIBC).

Materials and Methods

Urine samples from 440 patients undergoing surveillance for NMIBC were prospectively collected at five centres and evaluated using the Bladder EpiCheck test (NCT02647112). A multivariable nomogram and decision‐curve analysis (DCA) were used to evaluate the impact of Bladder EpiCheck on decision‐making when used in routine clinical practice. The test was designed to exclude recurrent disease.

Results

Data from 357 patients were available for analysis. The test had a specificity of 88% (95% confidence interval [CI] 84–91), a negative predictive value (NPV) of 94.4% (95% CI 91–97) for the detection of any cancer and an NPV of 99.3% for the detection of high‐grade cancer. In multivariable analysis, positive Bladder EpiCheck results were independently associated with any and high‐grade disease recurrence (odds ratio [OR] 18.1, 95% CI 8.7–40.2; P < 0.001 and OR 78.3, 95% CI 19.2–547; P < 0.001). The addition of Bladder EpiCheck to standard variables improved its predictive ability for any and high‐grade disease recurrence by a difference of 16% and 22%, respectively (area under the curve 85.9% and 96.1% for any and high‐grade cancer, respectively). DCA showed an improvement in the net benefit relative to cystoscopy over a large threshold of probability, resulting in a significant reduction in unnecessary investigations. These results were similar in subgroups assessing the impact of specific clinical features.

Conclusions

Bladder EpiCheck is a robust high‐performing diagnostic test in patients with NMIBC undergoing surveillance that can potentially reduce the number of unnecessary investigations.

An up-to-date catalog of available urinary biomarkers for the surveillance of non-muscle invasive bladder cancer

OBJECTIVES

With the advent of novel genomic and transcriptomic technologies, new urinary biomarkers have been identified and tested for bladder cancer (BCa) surveillance. To summarize the current status of urinary biomarkers for the detection of recurrence and/or progression in the follow-up of non-muscle invasive BCa patients, and to assess the value of urinary biomarkers in predicting response to intravesical Bacillus Calmette-Guerin (BCG) therapy.

METHODS AND MATERIALS

A medline/pubmed© literature search was performed. The performance of commercially available and investigational biomarkers has been reviewed. End points were cancer detection (recurrence), cancer progression, and response to BCG therapy.

RESULTS

The performance requirements for biomarkers are variable according to the clinical scenario. The clinical role of urinary biomarkers in the follow-up of non-muscle invasive BCa patients remains undefined. The FDA-approved tests provide unsatisfactory sensitivity and specificity levels and their use is limited. Fluorescence in situ hybridization (FISH) has been shown to be useful in specific scenarios, mostly as a reflex test and in the setting of equivocal urinary cytology. FISH and immunocytology could conceivably be used to assess BCG response. Recently developed biomarkers have shown promising results; upcoming large trials will test their utility in specific clinical scenarios in a manner similar to a phased drug development strategy.

CONCLUSIONS

Current commercially available urinary biomarker-based tests are not sufficiently validated to be widely used in clinical practice. Several novel biomarkers are currently under investigation. Prospective multicenter analyses will be needed to establish their clinical relevance and value.

Surgical checklist impact on recurrence-free survival of patients with non-muscle-invasive bladder cancer undergoing transurethral resection of bladder tumour

OBJECTIVES

To evaluate the impact of an eight-item surgical checklist (SC) on the recurrence-free survival (RFS) of patients with non-muscle-invasive bladder cancer (NMIBC) undergoing transurethral resection of bladder tumour (TURBT).

PATIENTS AND METHODS

A group of urologists at two tertiary referral centres, with expertise in bladder cancer, identified eight critical items that should be performed in every high-quality TURBT. An eight-item SC was prospectively implemented into clinical practice and the operative reports of TURBTs performed before and after implementation were reviewed. Results from both institutions were combined to estimate the impact of introducing the SC on oncological outcomes. Multivariable logistic and Cox hazards regression analyses were performed to evaluate the impact of the SC on the presence of detrusor muscle in the TURBT specimen and on RFS, respectively.

RESULTS

The operative reports of 266 TURBTs performed after the SC implementation were reviewed and compared to those of 281 TURBTs performed prior to the SC introduction. The SC was independently associated with a significant improvement in RFS (P = 0.02). However, the introduction of the SC was not significantly associated with the presence of detrusor muscle in the surgical specimen (P = 0.4).

CONCLUSION

The use of an eight-item SC during TURBT in clinical practice increases the quality of operative reports thereby potentially improving individualised risk-stratification and care resulting in lower disease recurrence rates. Therefore, the introduction of a SC can be recommended to enhance oncological outcomes by improving surgical standardisation and operative reporting.

A systematic review and meta-analysis of lymphovascular invasion in patients treated with radical cystectomy for bladder cancer

PURPOSE

Lymphovascular invasion (LVI) is an important step in bladder cancer cell dissemination. We aimed to perform a systematic review and meta-analysis of the literature to assess the prognostic value of LVI in radical cystectomy (RC) specimens.

PATIENTS AND METHODS

A systematic review and meta-analysis of the last 10 years was performed using the MEDLINE, EMBASE, and the Cochrane libraries in July 2017. The analyses were performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement.

RESULTS

We retrieved 65 studies (including 78,107 patients) evaluating the effect of LVI on oncologic outcomes in patients treated with RC. LVI was reported in 35.4% of patients. LVI was associated with disease recurrence (pooled hazard ratio [HR] = 1.57; 95% CI: 1.45-1.70) and cancer-specific mortality (CSM) (pooled HR = 1.59; 95% CI: 1.48-1.73) in all studies regardless of tumor stage and node status (pT1-4 pN0-2). LVI was associated with recurrence and CSM in patients with node-negative bladder cancer (BC). In patients with node-negative BC, LVI rate increased and was associated with worse oncologic outcome. LVI had a lower but still significant association with disease recurrence and CSM in node-positive BC.

CONCLUSIONS

LVI is a strong prognostic factor of worse prognosis in patients treated with RC for bladder cancer. This association is strongest in node-negative BC, but it is also in node-positive BC. LVI should be part of all pathological reporting and could provide additional information for treatment-decision making regarding adjuvant therapy after RC.

Pseudoprogression and hyperprogression during immune checkpoint inhibitor therapy for urothelial and kidney cancer

Objectives

A small subset of patients treated with immune checkpoint inhibitors manifest atypical patterns of response, the so-called pseudoprogression (PP) and hyperprogression (HP). Their prevalence in urothelial (UC) and renal cancer (RCC) remains, to date, mostly uninvestigated. Therefore, we aimed to provide a summary of the current knowledge about PP and HP during immune checkpoint inhibitor therapy in UC and RCC patients.

Methods and materials

A systematic medline/pubmed^© literature search was performed. The atypical patterns of response to systemic immunotherapy were reviewed. Endpoints were PP and HP in UC and RCC.

Results

Tumors respond differently to immunotherapy compared to systemic chemotherapy. To evaluate response to immunotherapy, new guidelines (iRECIST) have been developed. To date, no studies focused on PP in UC and RCC, and the only way to evaluate its role is to take patients who respond to treatment beyond progression as surrogate for pseudoprogressors. PP seems to occur in a non-negligible rate of UC and RCC (from 1.5 to 17% and from 5 to 15%, respectively). The concept of HP, defined as a rapid progression after treatment, just took the first steps, and therefore, data from ongoing trials are awaited to elucidate its impact in genitourinary cancers.

Conclusions

PP and HP are not uncommon entities in UC and RCC patients, treated with PD-1/PD-L1 inhibitors. Further investigation is warranted to define which patients are likely to experience PP and could benefit from treatment beyond progression and which ones will instead rapidly experience progression despite treatment and should, therefore, avoid systemic immunotherapy.

PD-1 and PD-L1 inhibitors after platinum-based chemotherapy or in first-line therapy in cisplatin-ineligible patients: Dramatic improvement of prognosis and overall survival after decades of hopelessness in patients with metastatic urothelial cancer

Until recently, there were no true innovations in the management of locally advanced (aUC) and metastatic urothelial cancer (mUC) in the last three decades. Vinflunine has been approved by the EMA (European Medicines Agency) with only limited improvement compared to best supportive care in second line treatment. In addition, gemcitabine/cisplatin has been established as an alternative to methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC). The advent of checkpoint inhibitors (CPI) revolutionized the care of these patients, transforming a unanimously deadly disease into one with hope through sustained disease control. Five immune CPI have recently been approved for aUC/mUC by the US Food and Drug Administration (FDA) including atezolizumab, nivolumab, pembrolizumab, durvalumab and avelumab. All five CPI are FDA-approved as second-line therapy with atezolizumab and pembrolizumab also being approved for first-line therapy in cisplatin-ineligible patients. The rapid acceptance in the treatment algorithm of UC is based on the impressive clinical efficacy of these agents in some patients, combined with their excellent safety profile. These new agents are indeed the most important advancement in UC care. However, the challenge in the age of precision medicine is to identify the patients who are most likely to benefit from CPIs, as the majority of patients do not respond to CPI. Toward this goal, validation of clinical, molecular and imaging biomarkers that serve for prediction and monitoring of treatment response are of central necessity.

Nationwide analysis on the impact of socioeconomic land use factors and incidence of urothelial carcinoma

BACKGROUND

Incidence rates for urothelial carcinoma (UC) have been reported to differ between countries within the European Union (EU). Besides occupational exposure to chemicals, other substances such as tobacco and nitrite in groundwater have been identified as risk factors for UC. We investigated if regional differences in UC incidence rates are associated with agricultural, industrial and residential land use.

METHODS

Newly diagnosed cases of UC between 2003 and 2010 were included. Information within 364 administrative districts of Germany from 2004 for land use factors were obtained and calculated as a proportion of the total area of the respective administrative district and as a smoothed proportion. Furthermore, information on smoking habits was included in our analysis. Kulldorff spatial clustering was used to detect different clusters. A negative binomial model was used to test the spatial association between UC incidence as a ratio of observed versus expected incidence rates, land use and smoking habits.

RESULTS

We identified 437,847,834 person years with 171,086 cases of UC. Cluster analysis revealed areas with higher incidence of UC than others (p=0.0002). Multivariate analysis including significant pairwise interactions showed that the environmental factors were independently associated with UC (p<0.001). The RR was 1.066 (95% CI 1.052-1.080), 1.066 (95% CI 1.042-1.089) and 1.067 (95% CI 1.045-1.093) for agricultural, industrial and residential areas, respectively, and 0.996 (95% CI 0.869-0.999) for the proportion of never smokers.

CONCLUSION

This study displays regional differences in incidence of UC in Germany. Additionally, results suggest that socioeconomic factors based on agricultural, industrial and residential land use may be associated with UC incidence rates.

ABO Blood Group and Rhesus Factor Are Not Associated with Outcomes After Radical Cystectomy for Non-metastatic Urothelial Carcinoma of the Bladder

AIM

To investigate the role of ABO blood group and Rhesus factor as a predictor of outcome in patients undergoing radical cystectomy (RC) for non-metastatic urothelial carcinoma of the bladder.

MATERIALS AND METHODS

Data of 463 consecutive patients treated with RC between 1988 and 2003 were retrospectively analyzed. The effect on recurrence-free survival, and cancer-specific and overall mortality were assessed using the Kaplan-Meier and multivariable Cox regression methods.

RESULTS

Overall, 185 (41.3%), 190 (42.4%), 46 (10.3%) and 27 (6%) patients expressed O, A, B and AB phenotypes, respectively; 65 (14.5%) were Rhesus-negative. Median follow-up was 14.2 years (interquartile range=10.2-17.1 years). No individual blood group was associated with any clinicopathological characteristics whereas Rhesus-positive patients had a higher rate of pT4 disease (11% vs. 22%; p=0.02). ABO blood groups were not associated with outcomes. Rhesus-positive patients had an increased risk of shorter recurrence-free survival, and of cancer-specific and overall mortality compared to Rhesus-negative patients (all p<0.03). In multivariable analyses that adjusted for the effects of standard characteristics, this association disappeared.

CONCLUSION

The results of our study showed that neither ABO blood group nor Rhesus factor are associated with oncological outcomes. The clinical relevance of blood groups and Rhesus factor in bladder cancer remains questionable.

From novice to expert: analyzing the learning curve for MRI-transrectal ultrasonography fusion-guided transrectal prostate biopsy

PURPOSE

To investigate the learning curve of a novice in MRI/TRUS software fusion biopsy and to compare his results with the expert standard at our institution.

METHODS

Overall 126 MRI/TRUS fusion-guided transrectal biopsies were performed using an electromagnetic tracking ultrasonography platform. The learning progress of the novice was evaluated comparing his initial 42 procedures (group A) with his following 42 (group B). The institution's expert standard (group C), which was compared to the novice's groups, was defined by the expert's experience of 42 MRI/TRUS fusion biopsies. Primary learning curve parameters were targeted biopsy detection quotient and biopsy time.

RESULTS

Overall detection of prostate cancer was 64% (27/42), 62% (26/42) and 62% (26/42) in groups A, B and C, respectively. The median target biopsy detection quotient significantly increased (p = 0.04) in group B (0.75, interquartile range (IQR) 0.25-1.0) compared to group A. (0.33, IQR 0.2-0.5). Group C revealed a median detection quotient of 0.5 (IQR 0.25-0.76) that did not differ significantly from the novice's groups (p = 0.2). Median biopsy time was significantly higher in group A (45 min, IQR 33-50 min) compared to groups B (25 min, IQR 23-29 min) and C (24 min, IQR 16-46 min) (p < 0.01).

CONCLUSIONS

The present study revealed the individual learning curve of a novice in MRI/TRUS fusion biopsy and demonstrated significant learning progress regarding targeted biopsy detection quotient and biopsy time.

Resistance to nanoparticle albumin-bound paclitaxel is mediated by ABCB1 in urothelial cancer cells

Nanoparticle albumin-bound (nab)-paclitaxel appears to exhibit better response rates in patients with metastatic urothelial cancer of the bladder whom are pretreated with nab-paclitaxel compared with conventional paclitaxel. Paclitaxel may induce multidrug resistance in patients with cancer, while the mechanisms of resistance against paclitaxel are manifold. These include reduced function of pro-apoptotic proteins, mutations of tubulin and overexpression of the drug transporter adenosine 5′-triphosphate-binding cassette transporter subfamily B, member 1 (ABCB1). To evaluate the role of ABCB1 in nab-paclitaxel resistance in urothelial cancer cells, the bladder cancer cell lines T24 and TCC-SUP, as well as sub-lines with acquired resistance against gemcitabine (T24^rGEMCI²⁰ and TCC-SUP^rGEMCI²⁰) and vinblastine (T24^rVBL²⁰ and TCC-SUP^rVBL²⁰) were examined. For the functional inhibition of ABCB1, multi-tyrosine kinase inhibitors with ABCB1-inhibiting properties, including cabozantinib and crizotinib, were used. Additional functional assessment was performed with cell lines stably transduced with a lentiviral vector encoding for ABCB1, and protein expression was determined by western blotting. It was indicated that cell lines overexpressing ABCB1 exhibited similar resistance profiles to nab-paclitaxel and paclitaxel. Cabozantinib and crizotinib sensitized tumor cells to nab-paclitaxel and paclitaxel in the same dose-dependent manner in cell lines overexpressing ABCB1, without altering the downstream signaling of tyrosine kinases. These results suggest that the overexpression of ABCB1 confers resistance to nab-paclitaxel in urothelial cancer cells. Additionally, small molecules may overcome resistance to anticancer drugs that are substrates of ABCB1.

Lymphocyte-to-monocyte ratio and neutrophil-to-lymphocyte ratio as biomarkers for predicting lymph node metastasis and survival in patients treated with radical cystectomy

PURPOSE

To evaluate the role of lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) as pre-operative markers for predicting extravesical disease and survival outcomes in patients undergoing radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB).

MATERIALS AND METHODS

Data from 4335 patients undergoing RC for clinically non-metastatic UCB were analyzed. Multivariable logistic regression models were used to predict lymph node involvement and extravesical disease (defined as ≥pT3 and N0). Recurrence-free (RFS), cancer-specific (CSS), and overall survival (OS) were evaluated using multivariable Cox models. The accuracy of the models was assessed with receiver operating characteristics (ROC) curves and concordance-index.

RESULTS

Median LMR was 3.5 and median NLR was 2.7. Addition of LMR and NLR to a standard preoperative model improved its discrimination for prediction of lymph node metastasis by 4.5%. On multivariable analysis LMR and NLR independently predicted RFS, CSS, and OS. The discrimination of this model increased by adding LMR and NLR but was not significant.

CONCLUSIONS

LMR and NLR independently improved the preoperative prediction of lymph node metastasis and survival outcomes. As they are readily available, they could be integrated in a panel of preoperative markers helping selecting patients who have extravesical lymph node involvement and more aggressive disease.

Predictive models and prognostic factors for upper tract urothelial carcinoma: a comprehensive review of the literature

In the context of customized patient care for upper tract urothelial carcinoma (UTUC), decision-making could be facilitated by risk assessment and prediction tools. The aim of this study was to provide a critical overview of existing predictive models and to review emerging promising prognostic factors for UTUC. A literature search of articles published in English from January 2000 to June 2016 was performed using PubMed. Studies on risk group stratification models and predictive tools in UTUC were selected, together with studies on predictive factors and biomarkers associated with advanced-stage UTUC and oncological outcomes after surgery. Various predictive tools have been described for advanced-stage UTUC assessment, disease recurrence and cancer-specific survival (CSS). Most of these models are based on well-established prognostic factors such as tumor stage, grade and lymph node (LN) metastasis, but some also integrate newly described prognostic factors and biomarkers. These new prediction tools seem to reach a high level of accuracy, but they lack external validation and decision-making analysis. The combinations of patient-, pathology- and surgery-related factors together with novel biomarkers have led to promising predictive tools for oncological outcomes in UTUC. However, external validation of these predictive models is a prerequisite before their introduction into daily practice. New models predicting response to therapy are urgently needed to allow accurate and safe individualized management in this heterogeneous disease.

Dasatinib enhances tumor growth in gemcitabine-resistant orthotopic bladder cancer xenografts

Background

Systemic chemotherapy with gemcitabine and cisplatin is standard of care for patients with metastatic urothelial bladder cancer. However, resistance formation is common after initial response. The protein Src is known as a proto-oncogene, which is overexpressed in various human cancers. Since there are controversial reports about the role of Src in bladder cancer, we evaluated the efficacy of the Src kinase inhibitor dasatinib in the urothelial bladder cancer cell line RT112 and its gemcitabine-resistant sub-line RT112^rGEMCI²⁰ in vitro and in vivo.

Methods

RT112 urothelial cancer cells were adapted to growth in the presence of 20 ng/ml gemcitabine (RT112^rGEMCI²⁰) by continuous cultivation at increasing drug concentrations. Cell viability was determined by MTT assay, cell growth kinetics were determined by cell count, protein levels were measured by western blot, and cell migration was evaluated by scratch assays. In vivo tumor growth was tested in a murine orthotopic xenograft model using bioluminescent imaging.

Results

Dasatinib exerted similar effects on Src signaling in RT112 and RT112^rGEMCI²⁰ cells but RT112^rGEMCI²⁰ cells were less sensitive to dasatinib-induced anti-cancer effects (half maximal inhibitory concentration (IC₅₀) of dasatinib in RT112 cells: 349.2 ± 67.2 nM; IC₅₀ of dasatinib in RT112^rGEMCI²⁰ cells: 1081.1 ± 239.2 nM). Dasatinib inhibited migration of chemo-naive and gemcitabine-resistant cells. Most strikingly, dasatinib treatment reduced RT112 tumor growth and muscle invasion in orthotopic xenografts, while it was associated with increased size and muscle-invasive growth in RT112^rGEMCI²⁰ tumors.

Conclusion

Dasatinib should be considered with care for the treatment of urothelial cancer, in particular for therapy-refractory cases.

The effect of HER2 status on oncological outcomes of patients with invasive bladder cancer

PURPOSE

The aim of this study was to evaluate the overexpression of human epidermal growth factor receptor 2 (HER2) in patients with bladder cancer (BCa) and to assess its association with oncological outcomes.

METHODS

This retrospective single-center study included 354 patients with BCa treated with radical cystectomy (RC). HER2 status was assessed with immunohistochemistry and scored according to HercepTest. Conditional survival and competing risk regression were performed to assess the association between HER2 expression and survival outcomes.

RESULTS

HER2 was overexpressed in 36% of patients. HER2 overexpression was associated with features of tumor aggressiveness such as lymph-node metastases (P = 0.002). At a median follow-up of 123 months (interquartile range: 79-180), 160 patients (45%) experienced disease recurrence, 263 patients (74%) died and 157 (44%) died of cancer. On multivariable analyses, HER2 overexpression was not significantly associated with any oncological outcomes. Adding HER2 status to a model for the prediction of survival outcomes did not change the accuracy of the model for any of the outcomes. Interestingly, HER2 status significantly affected late disease recurrence (P = 0.05 for conditional survival at 24 months).

CONCLUSIONS

More than one third of RC patients overexpress HER2 in their tumors. HER2 overexpression was associated with features of biological and clinical aggressiveness. HER2 did not add prognostic significance to the standard established predictors of survival outcomes after RC. However, due to the high overexpression rate, it could represent a target for therapy in select advanced BCa tumors.

Not all NOTCH Is Created Equal: The Oncogenic Role of NOTCH2 in Bladder Cancer and Its Implications for Targeted Therapy

PURPOSE

Recent molecular analyses of bladder cancer open the door to significant advances in targeted therapies. NOTCH has been identified as a tumor suppressor in bladder cancer, but prior reports have focused on NOTCH1 Here we hypothesized that NOTCH2 is an oncogene suitable for therapeutic targeting in bladder cancer.

EXPERIMENTAL DESIGN

We studied genomic aberrations of NOTCH, compared survival and tumor progression according to NOTCH2 expression levels, and studied NOTCH2 function in vitro and vivo

RESULTS

We report a high rate of NOTCH2 copy number gain in bladder cancer. High NOTCH2 expression was identified especially in the basal subtype and in mesenchymal tumors. NOTCH2 activation correlated with adverse disease parameters and worse prognosis by immunohistochemistry. Forced overexpression of the intracellular domain of NOTCH2 (N2ICD) induced cell growth and invasion by cell-cycle progression, maintenance of stemness and epithelial-to-mesenchymal transition (EMT). These effects were abrogated by silencing of CSL, indicating that the effects were mediated through the canonical NOTCH signaling pathway. In an orthotopic xenograft model, forced overexpression of N2ICD increased growth, invasion, and metastasis. To explore the potential for therapeutic targeting of NOTCH2, we first silenced the receptor with shRNA and subsequently treated with a specific inhibitory antibody. Both interventions decreased cell growth, invasion, and metastasis in vitro and in the orthotopic xenograft model.

CONCLUSIONS

We have demonstrated that NOTCH2 acts as an oncogene that promotes bladder cancer growth and metastasis through EMT, cell-cycle progression, and maintenance of stemness. Inhibition of NOTCH2 is a rational novel treatment strategy for invasive bladder cancer. Clin Cancer Res; 22(12); 2981-92. ©2016 AACR.

What should be the patient's preference regarding the choice of hospital in the case of radical cystectomy? Evaluation of early complications after open radical cystectomy in a medium and high volume setting in one hospital

PURPOSE

This study compares early complications after cystectomy and urinary diversion (UD) stratified by the surgical focus and case load of two different department chairpersons in a single institution in two time periods. Creating clear data about complications that can affect the quality of life is an important tool for patients to decide whether and where to perform this extensive surgery.

HYPOTHESIS

A team of surgeons with a clear focus on pelvic surgery leads to lower complication rates in radical cystectomy.

MATERIALS AND METHODS

Radical cystectomy was performed in two separate time periods under the patronage of two different chairmen in the same university hospital. The patient data were analyzed retrospectively and the complications 30 days after surgery were assessed using the Clavien-Dindo classification.

RESULTS

Statistical analysis showed a significant difference in the severity of complications between the two time periods, A and B, in total (P<0.001). When placing patients into subgroups, significantly more complications in period A were also seen concerning sex (male, P<0.001; female, P=0.003), age (<70 years, P<0.001; >70 years, P≤50.001) tumor grade (low grade, P<0.001; high grade, P≤0.001), and UD (ileal conduit, P<0.001; neobladder, P<0.001). In a multivariable analysis, age (P=0.031) and type of UD (P=0.028) were determined as independent predictors for complications in period A. When joining the two periods together, the type of UD (P=0.0417), age (P=0.041), and the time periods (A/B) (P<0.001) show a significant association with the presence of complications.

CONCLUSION

This study compares for the first time surgical complications in two time periods with different case load and surgical focus in one department. Categorization shows that patients should prefer radical cystectomy in centers of excellence or a high-volume hospital in order to keep complications at the lowest possible level and thus have the highest benefit for oncologic outcome and quality of life.

Drug-Resistant Urothelial Cancer Cell Lines Display Diverse Sensitivity Profiles to Potential Second-Line Therapeutics

Combination chemotherapy with gemcitabine and cisplatin in patients with metastatic urothelial cancer of the bladder frequently results in the development of acquired drug resistance. Availability of cell culture models with acquired resistance could help to identify candidate treatments for an efficient second-line therapy. Six cisplatin- and six gemcitabine-resistant cell lines were established. Cell viability assays were performed to evaluate the sensitivity to 16 different chemotherapeutic substances. The activity of the drug transporter ATP-binding cassette transporter, subfamily B, member 1 (ABCB1, a critical mediator of multidrug resistance in cancer) was evaluated using fluorescent ABCB1 substrates. For functional assessment, cells overexpressing ABCB1 were generated by transduction with a lentiviral vector encoding for ABCB1, while zosuquidar was used for selective inhibition. In this study, 8 of 12 gemcitabine- or cisplatin-resistant cell lines were cross-resistant to carboplatin, 5 to pemetrexed, 4 to methotrexate, 3 to oxaliplatin, 5-fluorouracil, and paclitaxel, and 2 to cabazitaxel, larotaxel, docetaxel, topotecan, doxorubicin, and mitomycin c, and 1 of 12 cell lines was cross-resistant to vinflunine and vinblastine. In one cell line with acquired resistance to gemcitabine (TCC-SUP^rGEMCI²⁰), cross-resistance seemed to be mediated by ABCB1 expression. Our model identified the vinca alkaloids vinblastine and vinflunine, in Europe an already approved second-line therapeutic for metastatic bladder cancer, as the most effective compounds in urothelial cancer cells with acquired resistance to gemcitabine or cisplatin. These results demonstrate that this in vitro model can reproduce clinically relevant results and may be suitable to identify novel substances for the treatment of metastatic bladder cancer.

sE-cadherin serves as a diagnostic and predictive parameter in prostate cancer patients

BACKGROUND

Measurement of prostate-specific antigen (PSA) advanced the diagnostic and prognostic potential for prostate cancer (PCa). However, due to PSA's lack of specificity, novel biomarkers are needed to improve risk assessment and ensure optimal personalized therapy. A set of protein molecules as potential biomarkers was therefore evaluated in serum of PCa patients.

METHODS

Serum samples from patients undergoing radical prostatectomy (RPE) for biopsy-proven PCa without neoadjuvant treatment were compared to serum samples from healthy subjects. Preliminary screening of 119 proteins in 10 PCa patients and 10 controls was carried out by the Proteome Profiler Antibody Array. Those markers showing distinct differences between patients and controls were then further evaluated by ELISA in the serum of 165 PCa patients and 19 controls. Uni- and multivariate as well as correlation analysis were performed to test the capability of these molecules to detect disease and predict pathological outcome.

RESULTS

Screening showed that soluble (s)E-cadherin, E-selectin, MMP2, MMP9, TIMP1, TIMP2, Galectin and Clusterin warranted further evaluation. sE-Cadherin, TIMP1, Galectin and Clusterin were significantly over- and MMP9 under-expressed in PCa compared to controls. The concentration of sE-cadherin, MMP2 and Clusterin correlated negatively and that of MMP9 and TIMP1 positively with the Gleason Sum at prostatectomy. Only sE-cadherin significantly correlated with the highest Gleason pattern. Compared to serum PSA, sE-cadherin provided an independent and better matching predictive ability for discriminating PCas with an upgrade at RPE and aggressive tumors with a Gleason Sum ≥7.

CONCLUSIONS

sE-cadherin performed most favorably from a large panel of serum proteins in terms of diagnostic and predictive potential in curatively treatable PCa. sE-cadherin merits further investigation as a biomarker for PCa.

Intensified antineoplastic effect by combining an HDAC-inhibitor, an mTOR-inhibitor and low dosed interferon alpha in prostate cancer cells

A significant proportion of men diagnosed with prostate cancer (PCa) eventually develop metastatic disease, which progresses to castration resistance, despite initial response to androgen deprivation. As anticancer therapy has become increasingly effective, acquired drug resistance has emerged, limiting efficacy. Combination treatment, utilizing different drug classes, exemplifies a possible strategy to foil resistance development. The effects of the triple application of the histone deacetylase (HDAC) inhibitor valproic acid (VPA), the mammalian target of rapamycin inhibitor everolimus and low dosed interferon alpha (IFNα) on PCa cell growth and dissemination capacity were investigated. For that purpose, the human PCa cell lines, PC-3, DU-145 and LNCaP were treated with the combined regimen or separate single agents. Cell growth was investigated by the MTT dye reduction assay. Flow cytometry served to analyse cell cycle progression. Adhesion to vascular endothelium or immobilized collagen, fibronectin and laminin was quantified. Migration and invasion characteristics were determined by the modified Boyden chamber assay. Integrin α and β subtypes were investigated by flow cytometry, western blotting and RT-PCR. Integrin related signalling, Epidermal Growth Factor Receptor (EGFr), Akt, p70S6kinase and extracellular signal-regulated kinases (ERK)1/2 activation were also assessed. The triple application of VPA, everolimus and low dosed IFNα blocked tumour cell growth and dissemination significantly better than any agent alone. Antitumour effects were associated with pronounced alteration in the cell cycle machinery, intracellular signalling and integrin expression profile. Combining VPA, everolimus and low dosed IFNα might be a promising option to counteract resistance development and improve outcome in PCa patients.

The feasibility of ureteral tissue engineering using autologous veins: an orthotopic animal model with long term results

Background

In an earlier study we demonstrated the feasibility to create tissue engineered venous scaffolds in vitro and in vivo. In this study we investigated the use of tissue engineered constructs for ureteral replacement in a long term orthotopic minipig model. In many different projects well functional ureretal tissue was established using tissue engineering in animals with short-time follow up (12 weeks). Therefore urothelial cells were harvested from the bladder, cultured, expanded in vitro, labelled with fluorescence and seeded onto the autologous veins, which were harvested from animals during a second surgery. Three days after cell seeding the right ureter was replaced with the cell-seeded matrices in six animals, while further 6 animals received an unseeded vein for ureteral replacement. The animals were sacrificed 12, 24, and 48 weeks after implantation. Gross examination, intravenous pyelogram (IVP), H&E staining, Trichrome Masson’s Staining, and immunohistochemistry with pancytokeratin AE1/AE3, smooth muscle alpha actin, and von Willebrand factor were performed in retrieved specimens.

Results

The IVP and gross examination demonstrated that no animals with tissue engineered ureters and all animals of the control group presented with hydronephrosis after 12 weeks. In the 24-week group, one tissue engineered and one unseeded vein revealed hydronephrosis. After 48 weeks all tissue engineered animals and none of the control group showed hydronephrosis on the treated side. Histochemistry and immunohistochemistry revealed a multilayer of urothelial cells attached to the seeded venous grafts.

Conclusions

Venous grafts may be a potential source for ureteral reconstruction. The results of so far published ureteral tissue engineering projects reveal data up to 12 weeks after implantation. Even if the animal numbers of this study are small, there is an increasing rate of hydronephrosis revealing failure of ureteral tissue engineering with autologous matrices in time points longer than 3 months after implantation. Further investigations have to prove adequate clinical outcome and appropriate functional long-term results.

CCL2 Chemokine as a Potential Biomarker for Prostate Cancer: A Pilot Study

Purpose

Prostate specific antigen is not reliable in diagnosing prostate cancer (PCa), making the identification of novel, precise diagnostic biomarkers important. Since chemokines are associated with more aggressive disease and poor prognosis in diverse malignancies, we aimed to investigate the diagnostic relevance of chemokines in PCa.

Materials and Methods

Preoperative and early postoperative serum samples were obtained from 39 consecutive PCa patients undergoing radical prostatectomy. Serum from 15 healthy volunteers served as controls. Concentrations of CXCL12, CXCL13, CX3CL1, CCL2, CCL5, and CCL20 were measured in serum by Luminex. The expression activity of CXCR3, CXCR4, CXCR5, CXCR7, CXCL12, CXCL13, CX3CR1, CXCL1, CCR2, CCR5, CCR6, CCR7, CCL2, and CCL5 mRNA was assessed in tumor and adjacent normal tissue of prostatectomy specimens by quantitative real-time polymerase chain reaction. The associations of these chemokines with clinical and histological parameters were tested.

Results

The gene expression activity of CCL2 and CCR6 was significantly higher in tumor tissue compared to adjacent normal tissue. CCL2 was also significantly higher in the blood samples of PCa patients, compared to controls. CCL5, CCL20, and CX3CL1 were lower in patient serum, compared to controls. CCR2 tissue mRNA was negatively correlated with the Gleason score and grading.

Conclusion

Chemokines are significantly modified during tumorigenesis of PCa, and CCL2 is a promising diagnostic biomarker.

CCL2 promotes integrin-mediated adhesion of prostate cancer cells in vitro

PURPOSE

Chemokines undergo alterations during neoplasia. However, knowledge about their functional significance in prostate cancer (PCa) progression is still sparse. Since chemokine (C-C motif) ligand 2 (CCL2) is significantly up-regulated in patients with PCa, aim of the current study was to assess whether CCL2 contributes to invasive behavior of prostate cancer cells in vitro.

METHODS

The human PCa cell line PC3 was stimulated with CCL2. Cell growth was investigated by MTT dye reduction assay. Cell adhesion was analyzed by measuring attachment to a human endothelial cell (HUVEC) monolayer and immobilized collagen. Cell migration was assessed by a chemotactic assay. Integrin expression on the cell surface was evaluated by Western blot. Blocking studies were performed with anti-integrin α3, anti-integrin α6 and anti-integrin β4 monoclonal antibodies.

RESULTS

PC3 cell growth 72 h after CCL2 exposure was significantly increased, compared to controls. Activation of tumor cells by CCL2 significantly enhanced tumor cell adhesion to HUVEC and immobilized collagen. CCL2, added for 4 or 24 h, elevated α6 and β4 (4 > 24 h) integrin expression. α3 was enhanced after 4 h, but reduced after 24 h. Blocking either α3, α6 or β4 led to significant suppression of tumor cell binding to immobilized collagen.

CONCLUSIONS

CCL2 stimulates PCa cell adhesion and induces alterations in α3-, α6- and β4-integrin expression on the cell surface. Blocking these integrins leads to a significant reduction in cell adhesion.

Lyn tyrosine kinase regulates androgen receptor expression and activity in castrate-resistant prostate cancer

Castrate-resistant prostate cancer (CRPC) progression is a complex process by which prostate cells acquire the ability to survive and proliferate in the absence or under very low levels of androgens. Most CRPC tumors continue to express the androgen receptor (AR) as well as androgen-responsive genes owing to reactivation of AR. Protein tyrosine kinases have been implicated in supporting AR activation under castrate conditions. Here we report that Lyn tyrosine kinase expression is upregulated in CRPC human specimens compared with hormone naive or normal tissue. Lyn overexpression enhanced AR transcriptional activity both in vitro and in vivo and accelerated CRPC. Reciprocally, specific targeting of Lyn resulted in a decrease of AR transcriptional activity in vitro and in vivo and prolonged time to castration. Mechanistically, we found that targeting Lyn kinase induces AR dissociation from the molecular chaperone Hsp90, leading to its ubiquitination and proteasomal degradation. This work indicates a novel mechanism of regulation of AR stability and transcriptional activity by Lyn and justifies further investigation of the Lyn tyrosine kinase as a therapeutic target for the treatment of CRPC.

DHH is an independent prognosticator of oncologic outcome of clear cell renal cell carcinoma

PURPOSE

Aberrant HH signaling has proved important in the pathogenesis of several solid cancers. Limited in vitro analyses suggested an oncogenic role for HH in renal cell carcinoma. In this explorative study we sought to validate aberrant HH expression in patients with renal cell carcinoma.

MATERIALS AND METHODS

A tissue microarray was constructed from 140 radical nephrectomy specimens of patients with clear cell renal cell carcinoma. We performed immunohistochemistry for Ki67 and HH pathway biomarkers, including PTCH1, Smo, SHH, IHH, DHH, Gli1, Gli2 and Gli3. Staining intensity was measured by automated image processing and related to tumor stage and grade. The impact of biomarker expression on cancer specific survival was determined by univariate and multivariate Cox regression analysis.

RESULTS

Gli3, PTCH1, DHH and SHH demonstrated markedly higher expression in high than in low grade tumors. Tumor stage was not associated with marker expression. On univariate analysis DHH expression, and tumor grade and stage were associated with cancer specific survival. Multivariate analysis revealed that DHH, grade and stage were independent predictors of cancer specific survival.

CONCLUSIONS

To our knowledge we report for the first time that a biomarker of the HH pathway is associated with adverse pathological features and poor disease outcomes in patients with clear cell renal cell carcinoma. DHH may serve as an independent predictor of cancer specific survival in clear cell renal cell carcinoma cases. This supports further evaluation of HH signaling to validate the pathway as a target for novel therapy.

Fibroblast growth factor receptor 3 is a rational therapeutic target in bladder cancer

Activating mutations of fibroblast growth factor receptor-3 (FGFR3) have been described in approximately 75% of low-grade papillary bladder tumors. In muscle-invasive disease, FGFR3 mutations are found in 20% of tumors, but overexpression of FGFR3 is observed in about half of cases. Therefore, FGFR3 is a particularly promising target for therapy in bladder cancer. Up to now, most drugs tested for inhibition of FGFR3 have been small molecule, multityrosine kinase inhibitors. More recently, a specific inhibitory monoclonal antibody targeting FGFR3 (R3Mab) has been described and tested preclinically. In this study, we have evaluated mutation and expression status of FGFR3 in 19 urothelial cancer cell lines and a cohort of 170 American patients with bladder cancer. We have shown inhibitory activity of R3Mab on tumor growth and corresponding cell signaling in three different orthotopic xenografts of bladder cancer. Our results provide the preclinical proof of principle necessary to translate FGFR3 inhibition with R3Mab into clinical trials in patients with bladder cancer.

Hiding in plain view: genetic profiling reveals decades old cross contamination of bladder cancer cell line KU7 with HeLa

PURPOSE

KU7 is a popular urothelial carcinoma cell line that was isolated from the bladder of a patient at Keio University in 1980. It has subsequently been widely used in laboratories around the world. We describe how routine cell line authentication revealed that KU7 was cross contaminated almost 30 years ago with HeLa, a cervical carcinoma cell line.

MATERIALS AND METHODS

Presumed KU7 clones dating from 1984 to 1999 were provided by M.D. Anderson Cancer Center, Vancouver Prostate Centre, Kyoto University, Tokyo Medical University and Keio University. HeLa was obtained from ATCC. Genomic DNA was isolated and short tandem repeat analysis was performed at the M.D. Anderson Cancer Center Characterized Cell Line Core Facility, Johns Hopkins University Fragment Analysis Facility and RIKEN BioResource Center, Ibaraki, Japan. Comparative genomic hybridization was performed on a platform (Agilent Technologies, Santa Clara, California) at Vancouver Prostate Centre.

RESULTS

The short tandem repeat profile of all KU7 clones was an exact match with that of HeLa. Comparative genomic hybridization of all samples revealed an abundance of shared chromosomal aberrations. Slight differences in some genomic areas were explained by genomic drift in different KU7 clones separated by many years.

CONCLUSIONS

Our analysis identified that cross contamination of KU7 with HeLa occurred before 1984 at the source institution. All KU7 clones in the urological literature should be considered HeLa and experimental results should be viewed in this light. Our results emphasize the need to authenticate cell lines in oncological research.

Abstract 3536: Caulobacter crescentus as new intravesical treatment for bladder cancer

Introduction and Objectives: The standard of care for high risk non-muscle invasive bladder cancer is the intravesical instillation of Bacillus Calmette-Guérin (BCG), an attenuated strain of the pathogen Mycobacterium bovis, associated with significant side effects often ending treatment prematurely. Using nonpathogenic bacterial strains with anti-tumor activity would thus be beneficial. Caulobacter crescentus is a gram-negative, non-pathogenic fresh water bacterium that does not replicate in a mammalian host and therefore qualifies for having a good bio-safety profile. Caulobacter crescentus has previously been shown to have anti-tumor activity in a model of mammary carcinoma. The aim of this study was to evaluate the anti-tumor activity of intravesical administered Caulobacter cresecentus in an immuno-competent animal model for bladder cancer.

Materials and Methods: In vitro, the mouse bladder tumor cell line MBT-2, derived from C3H/He mice, was treated with increasing concentrations of Caulobacter crescentus (C.cresc.). Microscopy and growth assays were performed. In vivo, the same cell line, previously lenti-viral transduced with a luciferase gene (MBT-2 luc), was instilled in the bladder of 6 week old, female C3H/He mice (3×106 cells/50ul). Bioluminescent imaging was performed to determine tumor burden on day 5 and mice were randomized to treatment groups. Intravesical treatments (109 C.cresc. in 50ul of H2O or H2O as control) were performed on days 6, 8, 11 and 15 and tumor growth was examined by bioluminescence after i.p. injection of luciferin. Mice were euthanized on day 20 and mouse bladders processed for histology and immuno-histochemistry.

Results: In vivo, intravesical treatment of MBT-2 luc tumor bearing C3H/He mice showed a significant inhibition of tumor growth compared to the control group, while no side-effects due to the intravesical C.cresc. application were observed.

Additionally performed in vitro experiments revealed that incubation of MBT-2 cells with C.cresc. resulted in a concentration dependent growth inhibition.

Conclusions: These preliminary results support the safety and efficacy of Caulobacter crescentus as a novel intravesical treatment for bladder cancer. Further investigation is needed to reveal the exact mechanism of action and to distinguish, if a direct anti-tumor effect of C.cresc. or the host immune-response is the driving component of the anti-tumor effect.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3536. doi:10.1158/1538-7445.AM2011-3536

Abstract 234: Fibroblast growth factor receptor (FGFR)-3 as a suitable target in bladder cancer

Introduction and Objective: Mutations in the FGFR3 gene, which can confer constitutive activity, are found in up to 80% of low grade papillary bladder cancers (BC). Overexpression of FGFR3 has been detected in approximately half of high grade and invasive tumors. In this study we evaluate FGFR3 in a cohort of American patients and investigate the effect of targeting FGFR3 in pre-clinical models of bladder cancer.

Materials and Methods: DNA was extracted from 170 fresh frozen BC specimens using a commercial kit and PCR of exons 7 and 10 was performed. Mutation analysis was performed by ABI Big Dye Terminator Cycle Sequencing. FGFR3 expression was analyzed by immunohistochemistry in an overlapping cohort of 143 patients with BC. FGFR3 expression, phosphorylation and downstream signaling were measured in a panel of BC cell lines, and the efficacy of two small molecule inhibitors (TKI258 and BGJ398) was tested on signaling and 3H-thymidine incorporation. A specific inhibitory monoclonal antibody targeting FGFR3 was evaluated in an orthotopic xenograft model of BC. Tumor burden was measured with bioluminescent imaging.

Results: FGFR3 mutations were identified in 44 (26%) BC samples, including 28/50 (56%) of low grade papillary lesions. Overexpression of FGFR3 was noted in 53% of all BC specimens regardless of stage and grade, but not in normal urothelium. FGFR3 inhibition effectively abrogated constitutive phosphorylation of FGFR3 and p42/44MAPK in a subset of bladder cancer cell lines. A growth inhibitory effect was observed in the same cell lines. The growth of UC14 xenografts in the bladder of nude mice was inhibited by 40%.

Conclusion: These studies underline the potential clinical relevance of FGFR3 mutation and expression in bladder cancer. Furthermore, the preclinical investigations offer proof of principle for moving forward with clinical trials studying the administration of specific FGFR3 inhibitors in patients with bladder cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 234. doi:10.1158/1538-7445.AM2011-234

Abstract 3308: Differential expression of Notch-1 and Notch-2 correlates to invasive phenotype in bladder cancer cell lines

The Notch pathway plays a critical role in growth and differentiation, and is involved in cancer progression in different organ sites. Little is known about Notch in bladder cancer. In this study, we evaluated Notch-1 and Notch-2 expression in a panel of bladder cancer cell lines.

Thirteen bladder cancer cell lines with previously described invasive properties and epithelial/mesenchymal characteristics were screened for Notch-1 and Notch-2 expression by Western blot and real-time PCR. Immunohistochemistry (IHC) was performed on a tissue microarray (US Biomax, Inc., Rockville, MD) that included cores from 152 patients with bladder cancer. Alterations in gene expression after Notch-2 silencing with siRNA were measured by expression microarray in 3 cell lines. Genes that changed by at least 2-fold in all 3 cell lines were selected for further analysis. Wound healing assays were performed after treatment with Notch-2 siRNA versus scrambled siRNA. The Mann-Whitney test was performed for statistical analysis.

Epithelial cell lines with low invasive potential expressed Notch-1 at high and Notch-2 at low relative levels (P=0.03 and P&lt;0.01, respectively, compared to invasive cell lines). Highly invasive, mesenchymal cell lines expressed high levels of Notch-2 and low levels of Notch-1. These results were validated by Western blot and IHC (TMA). Microarray analysis revealed altered expression of genes related to epithelial to mesenchymal transition (EMT), protein and endosome trafficking, and cell-cell connections, when Notch-2 was silenced with siRNA. Notch-2 silencing decreased the migration of UC3 cells in the wound healing assay (P=0.02).

These results provide preliminary evidence for a role for Notch in the progression of bladder cancer and it is suggested that this may be related to EMT. Further investigation is needed to assess the suitability of Notch as a therapeutic target, and it would appear that selective inhibition of individual Notch receptors may be preferential over global inhibition.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3308.