Dan Theodorescu

Relationship between HLA class I antigen processing machinery component expression and the clinicopathologic characteristics of bladder carcinomas.

PurposeThe goal of this study was to analyze protein expression of antigen processing machinery (APM) components in bladder carcinoma (BC), and to assess the clinical significance of defects in their expression.Experimental designTissue from 167 cystectomies for primary BC was used to create a tissue microarray. 128 tumors were urothelial carcinoma (UC). Immunohistochemistry was performed using 14 monoclonal antibodies to APM components (β2-microglobulin, calnexin, calreticulin, delta, Z, MB1, LMP2, LMP7, LMP10, HLA class I heavy chain, tapasin, TAP1, TAP2 and ERp57) and MHC class I-related antigen (MICA). Sections of normal urothelium from six subjects were used as controls.ResultsAll APM components except MB1, LMP2 and TAP2 had significantly lower staining in UC than in normal urothelium. No significant differences were found in APM component scores between different grades of UC. Squamous cell carcinoma had the highest scores, with UC intermediate and other types of BC lowest. High-stage UC demonstrated significantly lower staining for calnexin, LMP2, LMP7 and LMP10 than low-stage UC. With mean 3.6xa0years follow up, significantly worse survival was associated with a higher delta score in UC (Pxa0=xa00.038) and a lower calreticulin score in all tumor types (Pxa0=xa00.028).ConclusionsMost APM components were downregulated in UC. High-stage UC had lower scores for immunoproteasome components compared to low-stage UC. Delta and calreticulin protein expression was associated with survival in UC and in all types of BC, respectively. These findings suggest that APM defects play a role in the clinical course of BC and should be considered in developing immunotherapeutic approaches for its control.

Determinants of long‐term quality of life and voiding function of patients treated with radical prostatectomy or permanent brachytherapy for prostate cancer

To assess the long‐term quality of life (QoL) outcomes of three treatments for localized prostate cancer: radical prostatectomy (RP); brachytherapy monotherapy (BTM); and BT combined with external beam radiotherapy (BTC).

Longitudinal Comparison of Sexual Function After 3-Dimensional Conformal Radiation Therapy or Prostate Brachytherapy

PURPOSEnThe risk of erectile dysfunction can influence treatment decisions for localized prostate cancer. To estimate the risk from 2 popular radiotherapies we compared erectile function and overall satisfaction with sexual function after 3-dimensional (D) conformal radiation therapy and transperineal prostate brachytherapy.nnnMATERIALS AND METHODSnA total of 128 patients with prostate cancer underwent 3-D conformal radiation therapy (median dose 70.2 Gy. to the planning target volume) and 60 underwent palladium transperineal prostate brachytherapy (median dose 90 or 115 Gy. to 80% of the prostate with or without external nonconformal beam radiation therapy. Of the 128 patients 47 (37%) also received a luteinizing hormone releasing hormone (LH-RH) agonist (3 to 4 months), whereas 26 (43%) of the 60 patients received external beam radiation therapy and LH-RH (8 to 9 months). We evaluated erectile function and overall satisfaction with questions from validated, self-administered questionnaires. Patients responded to the questions serially before any prostate cancer therapy and at regular followup visits thereafter. We used the time until a patient returned to baseline erectile function and overall satisfaction to compare treatment modalities.nnnRESULTSnMedian followup was 21 months. Of patients receiving 3-D conformal radiation therapy with or without LH-RH agonists 65% (95% CI 47% to 82%) and 67% (53% to 81%), respectively, returned to baseline overall satisfaction within 12 months after treatment versus 23% (9% to 50%) and 56% (38% to 75%) of the patients treated with transperineal prostate brachytherapy with or without external beam radiation therapy and LH-RH agonists, respectively. Reductions in overall satisfaction appeared to relate to changes in erectile function.nnnCONCLUSIONSnThese data suggest that in the absence of LH-RH agonist use 3-D conformal radiation therapy and transperineal prostate brachytherapy have a similar impact on erectile function and overall satisfaction. Differences observed in erectile function and overall satisfaction in the 2 groups of patients who received adjuvant LH-RH may be due to the different duration of therapy (3 versus 8 months). Longer followup will be needed to evaluate this hypothesis.

Profiling Bladder Cancer Organ Site-Specific Metastasis Identifies LAMC2 as a Novel Biomarker of Hematogenous Dissemination

Little is known about which genes mediate metastasis in bladder cancer, which accounts for much of the mortality of this disease. We used human bladder cancer cell lines to develop models of two clinically common metastatic sites, lung and liver, and evaluated their gene expression with respect to human tumor tissues. Parental cells were injected into either the murine spleen to generate liver metastases or tail vein to generate lung metastases with sequential progeny derived by re-injection and comparisons made of their organ-specific nature by crossed-site injections. Both genomic and transcriptomic analyses of organ-selected cell lines found salient differences and shared core metastatic profiles, which were then screened against gene expression data from human tumors. The expression levels of laminin V gamma 2 (LAMC2) contained in the core metastatic signature were increased as a function of human tumor stage, and its genomic location was in an area of gain as measured by comparative genomic hybridization. Using immunohistochemistry in a human bladder cancer tissue microarray, LAMC2 expression levels were associated with tumor grade, but inversely with nodal status. In contrast, in node-negative patients, LAMC2 expression was associated with visceral metastatic recurrence. In summary, LAMC2 is a novel biomarker of bladder cancer metastasis that reflects the propensity of cells to metastasize via either lymphatic or hematogenous routes.

The Ral GTPase pathway in metastatic bladder cancer: Key mediator and therapeutic target

Bladder cancer is a relatively common and strikingly costly malignancy. Here, we will focus on recent advances in our understanding of the molecular pathogenesis of metastatic bladder cancer, a stage of this disease curable in only a minority of patients. Our group has recently investigated the role of a class of small G-proteins known as the Ras-like or Ral GTPases and their role in this disease. These signaling proteins, regulated by the Ras pathway and other mechanisms, have been shown to be necessary for key cellular phenotypes associated with transformation or cancer progression in diverse cancer systems. In bladder cancer we have observed that these GTPases are overexpressed, are necessary for key phenotypes in models of bladder cancer progression, and finally, are essential for the regulation of expression of key molecules, including the prognostic marker and cell surface GPI-linked glycoprotein, CD24. These findings are reviewed here and suggest that Ral GTPases and their downstream pathways constitute key mediators of bladder cancer progression and may include targets for future therapeutic strategies.

Atypical small acinar proliferation: biopsy artefact or distinct pathological entity?

To determine if atypical small acinar proliferation (ASAP) represents minimally sampled prostate cancer not fully evaluated on a biopsy or a distinct pathological entity, by examining prostates removed at radical cystectomy, as a finding of ASAP of the prostate on needle‐core biopsy is closely associated with the detection of cancer on subsequent biopsy.

The Prognostic Value of Cell Cycle Gene Expression Signatures in Muscle Invasive, High-Grade Bladder Cancer

Abstract Background: Approximately half of patients with muscle invasive bladder cancer succumb to their disease. Previous work identified cell cycle related genes as a prognostic class of gene expression biomarkers in bladder cancer and found a specific 31-gene cell cycle proliferation (CCP) signature predicted outcome across multiple bladder cancer cohorts. However, the prognostic value of the CCP signature specifically in muscle invasive tumors was not evaluated. Objective: To determine the prognostic value of cycle related genes in patients with muscle invasive bladder cancers. Method: We collected all publicly available gene expression data for patients with high-grade, muscle invasive bladder cancer (8 cohorts, Nu200a=u200a458). We evaluated the CCP signature and two larger cell cycle gene sets: 1826 genes with a Gene Ontology (GO) annotation of “cell cycle” (GO-CCS) and 124 genes belonging to the “cell cycle” pathway in the KEGG pathway database (KEGG-CCS). An independently derived a sex identification gene signature (SIS) was developed as a positive control. Results: While SIS distinguished males from females in all cohorts with information about patient sex, the CCP signature was not prognostic in any of the cohorts we analyzed, and the GO-CCS and KEGG-CCS were never prognostic in more than 2 independent cohorts. Furthermore, neither the CCP, GO-CCS, nor KEGG-CCS signatures were consistently enriched in prognostic genes while SIS was enriched with genes associated with sex in all cohorts. Conclusions: Our findings suggest that cell cycle related genes have limited prognostic value in patients with high-grade, muscle invasive tumors. Their usefulness in predicting progression of noninvasive disease and patient response to chemotherapy remains to be determined.

Molecular Nomograms for Predicting Prognosis and Treatment Response

Human bladder cancer constitutes a heterogeneous disease characterized by, among its most common variant in Western societies, urothelial carcinoma (UC), two distinct nosologic entities: These are non muscle-invasive UC (NMIUC) and muscle-invasive UC (MIUC), which present specific management questions and are mediated by different molecular pathologic mechanisms. Logically, if differential molecular machinery can be demonstrated to underpin these pathologic states, theoretically, molecular biomarkers can be discovered to prognosticate disease course or predict susceptibility to therapeutic intervention. Thus, while NMIUC may be managed with some success through endoscopic resection, with or without adjuvant immuno- or chemotherapy (Dalbagni 2007), prediction of recurrence or evolution to MIUC is an essential prognostic challenge, as is prediction of metastatic recurrence post cystectomy in de novo MIUC cases. Finally, selection of chemotherapy among locally advanced inoperable or metastatic cases, as well as in the adjuvant or neoadjuvant settings, presents a compelling need for molecularly guided therapy. In this chapter, we present and discuss the opportunity for molecular biomarkers of prognosis or prediction of therapeutic success, focusing on novel, multiplexed molecular biomarkers rather than single targets, and spotlighting cases where such strategies are tailored to the key clinical climacterics outlined above. Molecular data, or a combination of molecular data and traditional clinicopathologic data (Shariat et al. 2008a), can be used to construct models, which upon validation in large patient cohorts, are capable of contributing important prognostic or predictive information for the management of patients. Loosely defined, such a strategy may be called a nomogram (Shariat et al. 2008b).

Abstract LB-65: A gene expression predictor of pathological node stage of urothelial bladder cancer

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DCnnThe use of systemic neoadjuvant cisplatin-based chemotherapy prior to radical cystectomy for clinically muscle invasive but clinically node negative urothelial carcinoma (UC) has been shown in a recent meta-analysis of randomized trials to confer a 5-7% survival benefit (1). This relatively modest effect, therapy toxicity, and treatment delay in non-responsive patients has diminished enthusiasm and use of this approach. In contrast, defining patients that would benefit most would provide a compelling reason for use of such therapy. Despite negative clinical staging, up to 30% of patients have lymph node metastasis at cystectomy, the most important predictor for subsequent disease relapse. Here we develop a gene expression-based predictor of node positive disease at cystectomy in clinically node negative patients that could be applied before definitive resection using tissue from the patients endoscopic diagnosis. Importantly, we develop a predictor that can be applied on formalin fixed paraffin embedding (FFPE) tumor samples, for facile deployment of this clinical tool.nnWe first performed an analysis of correlation of gene expression between fresh frozen (FF) and FFPE across 32 paired tissues samples preserved both ways, using bootstrapping to select only array probes that maintain robust correlation irrespective of tissue preservation method. Using the “robust” gene set, we identified a subset of genes that were differentially expressed between node positive and node negative disease found at cystectomy in a cohort of 90 FFPE tumor specimens we profiled by oligonucleotide microarrays. A model based on these genes was then optimized for prediction of node positive disease on an independent set of 91 FF specimens profiled on the same microarray platform (2), using a weighted kNN algorithm. A final, 108-feature (probeset) predictor was then tested on a third cohort of 185 FFPE samples from a prospective randomized clinical trial (AUO-AB 05/95) (3). On the independent dataset, the predictor exhibited favorable discriminant characteristics (AUC=0.70, 95%CI 0.62 to 0.78, P<0.0001, ROC Analysis) for prediction of node metastasis at cystectomy in clinically node negative patients. Based on the performance on this prospectively collected dataset, we have developed a dual cutoff system, as has been used for other molecular classifiers (4), providing a threshold yielding a 50% PPV for a priori identification of high risk therapy candidates and a threshold yielding an 85% NPV for identification of low risk candidates to exclude from treatment. Multivariate logistic regression demonstrated this predictors performance was independently associated with nodal status when adjusting for clinicopathologic factors (P<0.001). We suggest that this strategy may aid in the decision of whether to use neoadjuvant chemotherapy and may help to close the gap between evidence in practice in this regard.nnReferences nn1. Cochrane Database Syst. Rev. 2005nn2. Sanchez-Carbayo. JCO 2005.nn3. Lehmann. JCO 2005.nn4. Paik. NEJM 2004.nnCitation 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 LB-65.