Assessing interactions between mdm-2, p53, and bcl-2 as prognostic variables in muscle-invasive bladder cancer treated with neo-adjuvant chemotherapy followed by locoregional surgical treatment

Predictors of response to neoadjuvant therapy in urothelial cancer

Neoadjuvant cisplatin-based chemotherapy (NACC) followed by radical cystectomy is the standard treatment for localized muscle-invasive bladder cancer (MIBC). Patients who achieve a complete pathological response following NACC have better overall survival than those with residual disease. However, a subset of patients does not derive benefit from NACC while experiencing chemotherapy-related side effects that may delay cystectomy, which can be detrimental. There is a need for predictive and prognostic biomarkers to better stratify patients who will derive benefits from NACC. This review summarizes the currently available literature on various predictors of response to neoadjuvant chemotherapy. Covered predictors include clinical factors, treatment regimens (including chemotherapy and immunotherapy), histological predictors, and molecular predictors such as DNA repair genes, p53, FGFR3, ERBB2, Bcl-2, EMMPRIN, survivin, choline-phosphate cytidylyltransferase-α, epigenetic markers, immunological markers, other molecular predictors and gene expression profiling. Further, we elaborate on the potential role of neoadjuvant immunotherapy and the correlative biomarkers of response.

Prediction of neo-adjuvant chemotherapy response in bladder cancer: the impact of clinical parameters and routine biomarkers

PURPOSE

To investigate the role of clinical parameters and immunohistochemical (IHC) biomarkers in their feasibility to predict the effect of neo-adjuvant chemotherapy (NAC) in patients with muscle-invasive urothelial bladder cancer (MIBC).

MATERIALS AND METHODS

The first 76 consecutive patients with MIBC treated with NAC and radical cystectomy in two University hospitals in Finland between 2008 and 2013 were chosen for this study. After excluding patients with non-urothelial cancer, less than two cycles of chemotherapy, no tissue material for IHC analysis or non-muscle-invasive bladder cancer in re-review, 59 patients were included in the final analysis. A tissue microarray block was constructed from the transurethral resection samples and IHC stainings of Ki-67, p53, Her-2 and EGFR were made. The correlations between histological features in transurethral resection samples and immune-histochemical stainings were calculated. The associations of clinicopathological parameters and IHC stainings with NAC response were evaluated. Factors affecting survival were estimated.

RESULTS

The complete response rate after NAC was 44%. A higher number of chemotherapy cycles was associated with better response to neo-adjuvant chemotherapy. No response to neo-adjuvant chemotherapy and female gender was associated with decreased cancer-specific survival. The IHC stainings used failed to show an association with neo-adjuvant chemotherapy response and overall or cancer specific survival.

CONCLUSIONS

Patients who do not respond to neo-adjuvant chemotherapy do significantly worse than responders. This study could not find clinical tools to distinguish responders from non-responders. Further studies preferably with larger cohorts addressing this issue are warranted to improve the selection of patients for neo-adjuvant chemotherapy.

FBXO16-mediated hnRNPL ubiquitination and degradation plays a tumor suppressor role in ovarian cancer

Heterogeneous nuclear ribonucleoprotein L (hnRNPL) is a type of RNA binding protein that highly expressed in a variety of tumors and plays a vital role in tumor progression. However, its post-translational regulation through ubiquitin-mediated proteolysis and the cellular mechanism responsible for its proteasomal degradation remains unclear. F-box proteins (FBPs) function as the substrate recognition subunits of SCF ubiquitin ligase complexes and directly bind to substrates. The aberrant expression or mutation of FBPs will lead to the accumulation of its substrate proteins that often involved in tumorigenesis. Here we discover FBXO16, an E3 ubiquitin ligase, to be a tumor suppressor in ovarian cancer, and patients with the relatively high expression level of FBXO16 have a better prognosis. Silencing or depleting FBXO16 significantly enhanced ovarian cancer cell proliferation, clonogenic survival, and cell invasion by activating multiple oncogenic pathways. This function requires the F-box domain of FBXO16, through which FBXO16 assembles a canonical SCF ubiquitin ligase complex that constitutively targets hnRNPL for degradation. Depletion of hnRNPL is sufficient to inactive multiple oncogenic signaling regulated by FBXO16 and prevent the malignant behavior of ovarian cancer cells caused by FBXO16 deficiency. FBXO16 interacted with the RRM3 domain of hnRNPL via its C-terminal region to trigger the proteasomal degradation of hnRNPL. Failure to degrade hnRNPL promoted ovarian cancer cell proliferation in vitro and tumor growth vivo, phenocopying the deficiency of FBXO16 in ovarian cancer.

Heterogeneous nuclear ribonucleoprotein (hnRNPL) in cancer

Heterogeneous nuclear ribonucleoprotein L (hnRNPL) is a type of RNA binding protein that is mainly located in the nucleus. hnRNPL protein, encoded by the gene located at 19q13.2, is an important member of the hnRNP family. In recent years, studies have shown that hnRNPL is highly expressed in a variety of tumors and plays a vital role in tumor progression. hnRNPL promotes various biological processes of tumor cells, including proliferation, migration and invasion. In this review, we discuss the clinical significance of hnRNPL by reviewing the mechanism of hnRNPL in the tumorigenesis of various cancers.

Is Bcl-2 a predictive marker of neoadjuvant chemotherapy response in patients with urothelial bladder cancer undergoing radical cystectomy?

Background: Response to neoadjuvant cisplatin treatment in bladder cancer has been linked to expression of Bcl-2 protein by cancer cells. The objective of this study was to test Bcl-2 as a predictive marker of neoadjuvant cisplatin chemotherapy response in a patient cohort from randomized cystectomy trials. Methods: Tumor samples were taken from 247 patients with T2-T4 bladder cancer enrolled in two randomized trials comparing cystectomy with or without neoadjuvant chemotherapy. Tissue microarrays from pre-intervention transurethral resection specimens were assessed for Bcl-2 protein status by immunohistochemistry. Extension of staining above 10% was regarded as positive. Downstaging and survival ratios in relation to Bcl-2 immunoreactivity and neoadjuvant chemotherapy utilization were calculated using the log rank test and multivariate Cox proportional hazards regression analyses. Results: Bcl-2 expression was positive in 38% and negative in 62% of the 236 evaluable patients. Bcl-2 negative patients receiving neoadjuvant chemotherapy had a significant increase in survival (p = 0.009), while Bcl-2 positive patients showed no difference (p = 0.4). However, the interaction variable between neoadjuvant chemotherapy and biomarker status was not significant (p = 0.38). When the prognostic value was assessed in the no-chemotherapy group, 5-year overall survival times were significantly better among Bcl-2 positive patients than among Bcl-2 negative patients (42 months vs 33 months, p = 0.04), but again Bcl-2 status did not remain independent when other factors were adjusted. Also, in a multivariate analysis with all patients, Bcl-2 was not significant. Conclusions: Bcl-2 status is not an independent predictor of neoadjuvant cisplatin chemotherapy response and is not prognostic in muscle-invasive bladder cancer.

Effects of multi and selective targeted tyrosine kinase inhibitors on function and signaling of different bladder cancer cells

BACKGROUND

Signaling of receptor tyrosine kinases (RTK) is dysregulated in various malignancies including bladder cancer. RTKs trigger pro-proliferative, anti-apoptotic and metastatic signaling pathways. Here, we assessed the effects of a selective tyrosine kinase inhibitor (TKI) (BGJ398) targeting fibroblast growth factor receptor (FGFR) and a pan-TKI (TKI258) targeting (FGFR), platelet derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor (VEGFR) in bladder cancer cells.

METHODS

Levels of mRNA transcripts were measured in nine human cell lines by quantitative RT-PCR. Cell function was assessed for viability, colony formation, migration, apoptosis and proliferation. Protein mediators of signal transduction were measured by Western-blot.

RESULTS

mRNA transcripts encoding RTK-related components, transcription factors, epithelial and mesenchymal transition (EMT) markers as well as cell cycle and apoptotic factors were determined in the cell lines. Principal component analysis ordered one epithelial-like cell cluster (5637, BFTC-905, MGHU4, RT112) and one mesenchymal-like cell cluster (T24, UMUC3, HU456, TCC-SUP). Cell response scores towards TKI258 and BGJ398 treatment were heterogeneous between cell lines and correlated with certain transcript levels. Analysis of signal transduction pathways revealed inhibition of fibroblast growth factor receptor (FGFR) signaling and induction of cell cycle dependent kinase (CDKN1A, p21) in epithelial-like cells differing in this regard from responses to mesenchymal-like cells that exhibited inhibition of mitogen-activated protein kinase (MAPK).

CONCLUSION

RTK and EMT related transcript analysis separate bladder cancer cells in two clusters. Functional responses towards TKI258 and BGJ398 treatment of bladder Fcancer cells were heterogeneous with deviating effects on signaling and possibly different therapeutic outcome.

Molecular Prognostication in Bladder Cancer

Clinical outcomes for patients with bladder cancer have largely remained unchanged over the last three decades despite improvements in surgical techniques, perioperative therapies, and postoperative management. Current management still heavily relies on pathologic staging that does not always reflect an individual patient's risk. The genesis and progression of bladder cancer is now increasingly recognized as being a result of alterations in several pathways that affect the cell cycle, apoptosis, cellular signaling, gene regulation, immune modulation, angiogenesis, and tumor cell invasion. Multiplexed assessment of biomarkers associated with alterations in these pathways offers novel insights into tumor behavior while identifying panels that are capable of reproducibly predicting patient outcomes. Future management of bladder cancer will likely incorporate such prognostic molecular models for risk stratification and treatment personalization.

HnRNP-L mediates bladder cancer progression by inhibiting apoptotic signaling and enhancing MAPK signaling pathways

Heterogeneous nuclear ribonucleoprotein L (hnRNP-L) is a promoter of various kinds of cancers, but its actions in bladder cancer (BC) are unclear. In this study, we investigated the function and the underlying mechanism of hnRNP-L in bladder carcinogenesis. Our results demonstrated that enhanced hnRNP-L expression in BC tissues was associated with poor overall survival of BC patients. Depletion of hnRNP-L significantly suppressed cell proliferation in vitro and inhibited xenograft tumor growth in vivo. Furthermore, downregulation of hnRNP-L resulted in G1-phase cell cycle arrest and enhanced apoptosis accompanied by inhibition of EMT and cell migration. All these cellular changes were reversed by ectopic expression of hnRNP-L. Deletion of hnRNP-L resulted in decreased expression of Bcl-2, enhanced expression of caspases-3, -6 and -9 and inhibition of the MAPK signaling pathway. These findings demonstrate that hnRNP-L contributes to poor prognosis and tumor progression of BC by inhibiting the intrinsic apoptotic signaling and enhancing MAPK signaling pathways.

Tp53 and its potential therapeutic role as a target in bladder cancer

INTRODUCTION

Despite more than 30 years of research on p53 resulting in >50,000 publications, we are now beginning to figure out the complexity of the p53 pathway, gene ontology and conformational structure of the molecule. Recent years brought great advances in p53 related drugs and the potencial ways in which p53 is inactivated in cancer. Areas covered: We searched for related publications on Pubmed and ClinicalTrial.gov using the following keywords 'p53, Tp53, p53 and bladder cancer, p53 and therapeutic target'. Relevant articles improved the understanding on p53 pathways and their potential as candidate to targeted therapy in bladder cancer. Expert opinion: Novel strategies developed to restore the function of mutants with chemical chaperones or by using compounds to improved pharmacokinetic properties are in development with potential to be applied in the oncology clinic. Other strategies targeting aberrantly overexpressed p53 regulators with wild-type p53 are also an active area of research. In particular, studies inhibiting the interaction of p53 with its negative regulators MDMX and MDM2 are an important field in drug discovery. Small molecules for inhibition of MDM2 are now in clinical trials process. However, personalized anticancer therapy might eventually advance through analyses of p53 status in cancer patients.

Molecular substratification of bladder cancer: moving towards individualized patient management

Despite advances in surgical techniques, perioperative therapies and postoperative management, outcomes for patients with bladder cancer have largely remained unchanged. Current management of bladder cancer still relies on pathologic staging that does not always reflect the risk for an individual patient. Studies assessing molecular alterations in individual tumors are offering insights into the myriad of cellular pathways that are deregulated in bladder tumorigenesis and progression. Alterations in pathways involved in cell-cycle regulation, apoptosis, cell signaling, angiogenesis and tumor-cell invasion have been shown to influence disease behavior. High-throughput assays are now allowing multiplexed assessment of biomarker alterations, thereby enabling characterization of novel molecular subtypes of bladder cancer. Such approaches have also been used for discovery and validation of robust prognostic molecular signatures. The future of bladder cancer management will rely on the use of validated multimarker panels for risk stratification, optimal surgical management, and theranostic strategies to identify and target specific alterations in individual tumors.

Selective organ preservation for the treatment of muscle-invasive transitional cell carcinoma of the bladder: a review of current and future perspectives

Radical treatment remains underutilized for those with muscle-invasive bladder cancer. Radical radiotherapy, in particular, continues to be perceived by many as reserved only for patients unfit for cystectomy. However, with concurrent use of radiosensitizers, radiotherapy can achieve excellent local control and survival comparable to modern surgical series, thus presenting a real alternative to surgery. The possibility of further enhancing patient outcome is likely to come from both advances in radiotherapy treatment delivery and appropriate candidate selection. Growing evidence from selective bladder preservation trials demonstrate long term survival with functional organ preservation. In the era of personalized medicine, we review the evidence supporting an individualized treatment approach, in particular case selection for radical radiotherapy.

Molecular determinants of response to cisplatin-based neoadjuvant chemotherapy

PURPOSE OF REVIEW

Neoadjuvant chemotherapy followed by cystectomy improves survival compared with surgery alone. To prevent overtreatment is of outmost importance to define molecular predictors of response for patient selection. We present the currently available data outlining a variety of potential markers to aid for a personalized decision-making process.

RECENT FINDINGS

Apart from p53, other markers of cell cycle regulation and apoptosis such as p21WAF1/CIP1 (p21) gene, Bcl-2, mouse double minute-2 and pRB have also been related to survival. The clinical relevance of epidermal growth factor receptor and HER2 expression has also been investigated with no success. Regarding Ki67, overexpressing tumors may potentially benefit from neoadjuvant therapy and conversely overexpression of vascular endothelial growth factor and bFGF have been linked to resistance to cisplatin-induced apoptosis. The role of multidrug resistance gene 1 and excision repair cross-complementing rodent repair deficiency complementation group 1 supports that enhanced DNA repair in the tumor decreases the benefit of platinum-based treatment. A 20-gene expression model has shown to predict lymph node involvement, helping on decision-making. A gene expression profiling has been proposed as predictive for response to neoadjuvant chemotherapy.

SUMMARY

Predictive markers will eventually aid in the selection of patients that most likely benefit from preoperative treatment. In the coming years, a panel of markers will become available to achieve the predicted goal.

Advanced urothelial carcinoma: next-generation sequencing reveals diverse genomic alterations and targets of therapy

Although urothelial carcinoma (UC) of the urinary bladder generally portends a favorable prognosis, metastatic tumors often follow an aggressive clinical course. DNA was extracted from 40 μm of formalin-fixed, paraffin-embedded (FFPE) sections from 35 stage IV UCs that had relapsed and progressed after primary surgery and conventional chemotherapy. Next-generation sequencing (NGS) was performed on hybridization-captured, adaptor ligation-based libraries for 3320 exons of 182 cancer-related genes plus 37 introns from 14 genes frequently rearranged in cancer to at an average sequencing depth of 1164 × and evaluated for all classes of genomic alterations (GAs). Actionable GAs were defined as those impacting the selection of targeted anticancer therapies on the market or in registered clinical trials. A total of 139 GAs were identified, with an average of 4.0 GAs per tumor (range 0-10), of which 78 (56%) were considered actionable, with an average of 2.2 per tumor (range 0-7). Twenty-nine (83%) cases harbored at least one actionable GA including: PIK3CA (9 cases; 26%); CDKN2A/B (8 cases; 23%); CCND1 (5 cases; 14%); FGFR1 (5 cases; 14%); CCND3 (4 cases; 11%); FGFR3 (4 cases; 11%); MCL1 (4 cases; 11%); MDM2 (4 cases; 11%); EGFR (2 cases, 6%); ERBB2 (HER2/neu) (2 cases, 6%); NF1 (2 cases, 6%) and TSC1 (2 cases, 6%). Notable additional alterations included TP53 (19 cases, 54%) and RB1 (6 cases; 17%). Genes involved in chromatin modification were altered by nonsense mutation, splice site mutation or frameshift indel in a mutually exclusive manner in nearly half of all cases including KDM6A (10 cases; 29%) and ARID1A (7 cases; 20%). Comprehensive NGS of 35 UCs of the bladder revealed a diverse spectrum of actionable GAs in 83% of cases, which has the potential to inform treatment decisions for patients with relapsed and metastatic disease.

Germline single nucleotide polymorphisms associated with response of urothelial carcinoma to platinum-based therapy: the role of the host

BACKGROUND

Variations in urothelial carcinoma (UC) response to platinum chemotherapy are common and frequently attributed to genetic and epigenetic variations of somatic DNA. We hypothesized that variations in germline DNA may contribute to UC chemosensitivity.

PATIENTS AND METHODS

DNA from 210 UC patients treated with platinum-based chemotherapy was genotyped for 80 single nucleotide polymorphisms (SNPs). Logistic regression was used to examine the association between SNPs and response, and a multivariable predictive model was created. Significant SNPs were combined to form a SNP score predicting response. Eleven UC cell lines were genotyped as validation.

RESULTS

Six SNPs were significantly associated with 101 complete or partial responses (48%). Four SNPs retained independence association and were incorporated into a response prediction model. Each additional risk allele was associated with a nearly 50% decrease in odds of response [odds ratio (OR) = 0.51, 95% confidence interval 0.39-0.65, P = 1.05 × 10(-7)). The bootstrap-adjusted area under the curves of this model was greater than clinical prognostic factors alone (0.78 versus 0.64). The SNP score showed a positive trend with chemosensitivity in cell lines (P = 0.115).

CONCLUSIONS

Genetic variants associated with response of UC to platinum-based therapy were identified in germline DNA. A model using these genetic variants may predict response to chemotherapy better than clinical factors alone.

Prognostic value of apoptotic activity in muscle-invasive bladder cancer

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BRCA1 mRNA expression and outcome to neoadjuvant cisplatin-based chemotherapy in bladder cancer

BACKGROUND

neoadjuvant chemotherapy has shown a modest benefit in muscle-invasive bladder cancer patients; however, the subset of patients most likely to benefit has not been identified. BRCA1 plays a central role in DNA repair pathways and low BRCA1 expression has been associated with sensitivity to cisplatin and longer survival in lung and ovarian cancer patients.

PATIENTS AND METHODS

we assessed BRCA1 messenger RNA expression levels in paraffin-embedded pre-treatment tumor samples obtained by transurethral resection from 57 patients with locally advanced bladder cancer subsequently treated with neoadjuvant cisplatin-based chemotherapy. BRCA1 levels were divided into terciles and correlated with pathological response and survival.

RESULTS

a significant pathological response (pT0-1) was attained in 66% (24 of 39) of patients with low/intermediate BRCA1 levels compared with 22% (4 of 18) of patients with high BRCA1 levels (P = 0.01). Median survival was 168 months in patients with low/intermediate levels and 34 months in patients with high BRCA1 levels (P = 0.002). In the multivariate analysis for survival, only BRCA1 expression levels and lymphovascular invasion emerged as independent prognostic factors.

CONCLUSIONS

our data suggest that BRCA1 expression may predict the efficacy of cisplatin-based neoadjuvant chemotherapy and may help to customize therapy in bladder cancer patients.

Strategies for molecular expression profiling in bladder cancer

Carcinoma of the urinary bladder involves alterations in multiple cellular pathways that dictate the pathology of the disease and clinical outcome of the patient. This includes alterations in regulation of the cell cycle, apoptotic mechanisms, signal transduction and tumor angiogenesis. Interrogation of alterations in multiple molecules associated with these pathways is leading to the development of biomarker panels that are capable of predicting an individual patient's outcome or response to specific treatments. With respect to gene expression profiling, two broad approaches may be identified: a global approach and a pathway-specific approach. The global approach involves a high-throughput effort to profile the entire genome, while the pathway-specific approach quantifies select genes across several pathways. While the former has a high potential for discovery of novel signatures, the latter is important in generating reproducible and concise panels that have the potential for rapid clinical implementation. A combination of both these approaches is needed for the identification and validation of robust marker panels of potential clinical importance in bladder cancer.

Biomarkers in bladder cancer

Detailed molecular insights into bladder cancer biology might allow more detailed prognostication and optimization of treatment with the objective of improving patient outcome and quality of life. However, in bladder cancer research the search for biomarkers has been called into question and has even obtained notoriety. It is unlikely that any single marker will be able to improve prognostication for patients with bladder cancer above and beyond grade and stage, but a combination of multiple independent markers might more precisely predict the outcome. From a previous review, we identified seven biomarkers to study within the setting of the Bladder Cancer Prognosis Programme (BCPP), a 5-year multicentre programme of research based at the University of Birmingham and funded by Cancer Research UK, investigating their effectiveness in predicting recurrence and progression. As part of the ongoing quality-assurance process for BCPP we present an updated review of our selected biomarkers, as well as highlighting other recent important developments in bladder cancer research.

Molecular pathogenesis and diagnostics of bladder cancer

Despite elaborate characterization of the risk factors, bladder cancer is still a major epidemiological problem whose incidence continues to rise each year. Urothelial carcinoma is now recognized as a disease of alterations in several cellular processes. The more prevalent, less aggressive, recurrent, noninvasive tumors are characterized by constitutive activation of the Ras-MAPK pathway. The less common but more aggressive invasive tumors, which have a higher mortality rate, are characterized by alterations in the p53 and retinoblastoma pathways. Several diagnostic tests have attempted to identify these molecular alterations in tumor cells exfoliated in the urine, whereas prognostic tests have tried to identify aberrations so as to predict tumor behavior and identify therapeutic targets. The future of bladder cancer patient management will rely on the use of molecular tests to reliably diagnose the presence of disease, predict individual tumor behavior, and suggest potential targeted therapeutics.

Molecular alterations associated with bladder cancer initiation and progression

Bladder cancer is the fifth most commonly diagnosed non-cutaneous solid malignancy, and the second most commonly diagnosed genitourinary malignancy amongst people living in the United States, where it is estimated that more than 61,000 new cases of bladder cancer will be diagnosed in the year 2008. Approximately 90% of malignant tumors arising in the urinary bladder are of epithelial origin, the majority being transitional cell carcinomas. Early stage bladder tumors have been classified into two groups with distinct behavior and unique molecular profiles: low grade tumors (always papillary and usually superficial), and high-grade tumors (either papillary or non-papillary, and often invasive). Clinically, superficial bladder tumors (stages Ta and Tis) account for 75% to 85% of neoplasms, while the remaining 15% to 25% are invasive (T1, T2-T4) or metastatic lesions at the time of initial presentation. Studies from the author's group and others have revealed that distinct genotypic and phenotypic patterns are associated with early versus late stages of bladder cancer. Most importantly, early superficial diseases appear to segregate into two main pathways. Superficial papillary bladder tumors are characterized by gain-of-function mutations, mainly affecting classical oncogenes such as RAS and FGFR3. Deletions of chromosome 9, mainly allelic losses on the long arm (9q) are also frequent events in these tumors. Such genetic alterations are observed in most if not all superficial papillary non-invasive tumors (Ta), but only in a small subset of invasive bladder neoplasms. Flat carcinoma in situ (Tis) and invasive tumors are characterized by loss-of-function mutations, affecting the prototype tumor suppressor genes, including p53, RB and PTEN. These alterations are absent or very rare in the Ta tumors analyzed, but have been frequently identified in invasive bladder carcinomas. Based on these data, a novel model for bladder tumor progression has been proposed in which two separate genetic pathways characterize the evolution of superficial bladder neoplasms. Numerous individual molecular markers have been identified in the tissue specimens that correlate to some extent with tumor stage, and possibly with prognosis in bladder cancer. However, these molecular prognosticators do not play a role in the clinical routine management of patients with bladder tumors, mainly due to lack of large prospective validation studies. Thus, the need for development of specific tissue and serum tumor markers for prognostic stratification remains. The advent of high-throughput microarrays technologies allows comprehensive discovery of targets relevant in bladder cancer progression, which could be translated into new approaches for drug and biomarker development. Further investigation is warranted to define novel biomarkers specific for bladder cancer patients based on the molecular alterations of tumor progression, and multiplexed strategies for clinical management.

Prognostic value of apoptosis-related markers in urothelial cancer of the upper urinary tract

We investigated the expression of apoptosis-related markers and their association with the clinical outcomes of patients with urothelial carcinoma of the upper urinary tract. A total of 112 patients with urothelial carcinoma of the upper urinary tract that had surgery from March 1998 to July 2005 were included in the study. Tissue microarray slides were used for immunohistochemistry, and immunohistochemical staining was performed to investigate the association of apoptosis-related markers with clinical outcome. Apoptosis was confirmed by the TdT-mediated DUTP nick-end labeling method to obtain the apoptotic index. Survival analysis was performed according to the Kaplan-Meier method, and the Cox proportional hazard regression model was used to compare the relative influence of different prognostic factors. Among the 112 patients, 32 (28.6%) had altered expression of p53, 30 (26.8%) of bcl-2, 62 (55.4%) of bax, 27 (24.1%) of caspase-3, and 23 (20.5%) of survivin. The expression of p53 and caspase-3 was associated with the pathologic grade (P = .035 and P = .004, respectively). Altered expression of caspase-3 was associated with the pathologic stage (P = .016). The multivariate analysis showed that the expression of survivin (hazard ratio 2.91, 95% confidence interval 1.07-7.90, P = .036) and the apoptotic index (AI) (3.35, 1.06-10.56, P = .039), as well as the T and N stages (P = .043 and P = .010, respectively) were significantly associated with the disease-specific survival. Our results suggest that survivin expression and a high apoptotic index were poor prognostic factors for survival in patients with urothelial carcinoma of the upper urinary tract. These results may help to identify a subset of patients who require adjuvant therapy or closer follow-up.

High-resolution array-based comparative genomic hybridization of bladder cancers identifies mouse double minute 4 (MDM4) as an amplification target exclusive of MDM2 and TP53

PURPOSE

Loss of p53 function in urothelial cell carcinoma (UCC) by mutation or inactivation disrupts normal cell cycle checkpoints, generating a favorable milieu for genomic instability, a hallmark of UCC. The aim of this study was to characterize novel DNA copy number changes to identify putative therapeutic targets.

EXPERIMENTAL DESIGN

We report our findings using array comparative genomic hybridization on a whole-genome BAC/PAC/cosmid array with a median clone interval of 0.97 Mb to study a series of UCC cases. TP53 status was determined by direct sequencing, and an in-house tissue microarray was constructed to identify protein expression of target genes.

RESULTS

Array comparative genomic hybridization allowed identification of novel regions of copy number changes in addition to those already known from previous studies. A novel amplification previously unreported in UCC was identified at 1q32. A chromosome 1 tile path array was used to analyze tumors that showed gains and amplification; the mouse double minute 4 (MDM4) homologue was identified as the amplified gene. MDM4 mRNA expression correlated with copy number and tumor grade. Copy number changes of MDM4 and MDM2 occurred exclusively in tumors with wild-type p53. Overexpression of MDM4 corresponded to disruption of p53 transcriptional activity. Immunohistochemistry on an independent series by tissue microarray identified an inverse relationship between Mdm4 and Mdm2, with Mdm4 expression highest in invasive UCC.

CONCLUSION

The data indicate that gain/amplification and overexpression of MDM4 is a novel molecular mechanism by which a subset of UCC escapes p53-dependent growth control, thus providing new avenues for therapeutic intervention.

Outcome of patients who refuse cystectomy after receiving neoadjuvant chemotherapy for muscle-invasive bladder cancer

OBJECTIVES

To determine the outcome of patients who refuse cystectomy after receiving neoadjuvant chemotherapy for muscle-invasive bladder cancer.

METHODS

Between 1995 and 2001, 63 patients were evaluated who declined to undergo a planned cystectomy, because they achieved a complete clinical response to neoadjuvant cisplatin-based chemotherapy. Patient, tumor, and treatment features were assessed prospectively, and correlated in univariate and multivariate analyses with overall survival. The median follow-up was 86 mo and all patients were followed for more than 5 yr.

RESULTS

Forty patients (64%) survived, with 54% of them having an intact functioning bladder. The number and size of invasive tumors were strongly associated with overall survival. The most significant treatment variable predicting better survival was complete resection of the invasive tumor on re-staging transurethral resection before starting chemotherapy. Of 23 patients (36%) who subsequently died of disease, 19 (30%) relapsed with invasive cancer in the bladder. Over 90% of surviving patients had solitary, small, and low-stage invasive tumors completely resected, and 83% survived without relapses in the bladder.

CONCLUSIONS

Selected patients with muscle-invasive bladder cancers may survive after transurethral resection and neoadjuvant chemotherapy, and tumor features can identify which patients responding completely to chemotherapy may survive without cystectomy.