Muscle-invasive bladder carcinoma (MIBC) constitutes a heterogeneous group of tumors with a poor outcome. Molecular stratification of MIBC may identify clinically relevant tumor subgroups and help to provide effective targeted therapies. From seven series of large-scale transcriptomic data (383 tumors), we identified an MIBC subgroup accounting for 23.5% of MIBC, associated with shorter survival and displaying a basal-like phenotype, as shown by the expression of epithelial basal cell markers. Basal-like tumors presented an activation of the epidermal growth factor receptor (EGFR) pathway linked to frequent EGFR gains and activation of an EGFR autocrine loop. We used a 40-gene expression classifier derived from human tumors to identify human bladder cancer cell lines and a chemically induced mouse model of bladder cancer corresponding to human basal-like bladder cancer. We showed, in both models, that tumor cells were sensitive to anti-EGFR therapy. Our findings provide preclinical proof of concept that anti-EGFR therapy can be used to target a subset of particularly aggressive MIBC tumors expressing basal cell markers and provide diagnostic tools for identifying these tumors.

Purpose: Clinically useful molecular markers predicting the clinical course of patients diagnosed with non^muscle-invasive bladder cancer are needed to improve treatment outcome. Here, we validated four previously reported gene expression signatures for molecular diagnosis of disease stage and carcinoma in situ (CIS) and for predicting disease recurrence and progression. Experimental Design:We analyzed tumors from 404 patients diagnosed with bladder cancer in hospitals in Denmark, Sweden, England, Spain, and France using custom microarrays. Molecular classifications were compared with pathologic diagnosis and clinical outcome. Results: Classification of disease stage using a 52-gene classifier was found to be highly significantly correlated with pathologic stage (P < 0.001). Furthermore, the classifier added information regarding disease progression of T a or T 1 tumors (P < 0.001). The molecular 88-gene progression classifier was highly significantly correlated with progression-free survival (P < 0.001) and cancer-specific survival (P = 0.001). Multivariate Cox regression analysis showed the progression classifier to be an independently significant variable associated with disease progression after adjustment for age, sex, stage, grade, and treatment (hazard ratio, 2.3; P = 0.007). The diagnosis of CIS using a 68-gene classifier showed a highly significant correlation with histopathologic CIS diagnosis (odds ratio, 5.8; P < 0.001) in multivariate logistic regression analysis. Conclusion:This multicenter validation study confirms in an independent series the clinical utility of molecular classifiers to predict the outcome of patients initially diagnosed with non^muscle-invasive bladder cancer. This information may be useful to better guide patient treatment.Bladder cancer is a common malignant disease with 357,000 new cases and 145,000 deaths worldwide annually (1). Its prevalence is 3-to 8-fold higher than its incidence, making bladder cancer one of the most prevalent neoplasms, and hence a major burden for health care systems. The overall causespecific 5-year survival rate is about 65%. The disease presents in two different forms: non -muscle-invasive tumors (stages T a and T 1 ), usually treated with a local, organ-sparing approach, and muscle-invasive cancers (stages T 2 -T 4 ), usually requiring cystectomy if cure is intended.The non -muscle-invasive tumors account for f75% of newly diagnosed cases. A low proportion of patients are cured after tumor resection, but the tumors of more than 60% of these patients recur, and the frequency of recurrences has a significant effect on the patients' quality of life. Some of these patients also develop muscle-invasive tumors over time, the proportion ranging from very low for noninvasive papillary low-grade tumors to up to 60% progression for high-grade submucosa-invasive tumors (2, 3). Clinical risk factors for progression include invasion of the lamina propria, high grade, tumor size, occurrence of carcinoma in situ (CIS), and multiplicity or recurrence of ...

Urothelial bladder cancer (UBC) is rare in young patients and as a result little information as to tumor type and clinical course are available. We present clinicopathological data of a large series of patients less than 40 years with bladder carcinoma. We included in this retrospective study covering the period from 1992 to 2013 patients less than 40 years with a first diagnosis of bladder cancer. Lesions were classified according to the WHO 2004 classification by uropathologists of ten centers. Stage, grade, multifocality, smoking habits, recurrence, and survival were studied. The cohort comprised of 152 patients, 113 males and 39 females with a mean age of 33.2 years. The large majority of the patients (142) was diagnosed with an urothelial carcinoma, the ten others with various histopathological diagnoses. In the age group less than 30 years old, 40.3 % of the cases concerned a papillary urothelial neoplasia of low malignant potential (PUNLMP). In the age group over 30 years, the proportion of PUNLMP decreased to 27.2 %. Only 5.6 % of the UBC was associated with carcinoma in situ. In 14.1 %, a high grade muscle invasive UC was found; 7.0 % had lymph node and 4.9 % distant metastasis at time of presentation. Four patients presented with a history of schistosomiasis; all had an infiltrating carcinoma. After initial resection, 36 patients relapsed, 17 % as PUNLMP, 53 % as pTa low grade, and 30 % as pTa-pT2 high grade UC. During follow-up, 6 % of the patients died. PUNLMP is the most frequent entity in this patient group. It is important that the PUNLMP entity is maintained in future classification systems.

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