Arlene O. Siefker-Radtke

Identification of Distinct Basal and Luminal Subtypes of Muscle-Invasive Bladder Cancer with Different Sensitivities to Frontline Chemotherapy

Muscle-invasive bladder cancers (MIBCs) are biologically heterogeneous and have widely variable clinical outcomes and responses to conventional chemotherapy. We discovered three molecular subtypes of MIBC that resembled established molecular subtypes of breast cancer. Basal MIBCs shared biomarkers with basal breast cancers and were characterized by p63 activation, squamous differentiation, and more aggressive disease at presentation. Luminal MIBCs contained features of active PPARγ and estrogen receptor transcription and were enriched with activating FGFR3 mutations and potential FGFR inhibitor sensitivity. p53-like MIBCs were consistently resistant to neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy, and all chemoresistant tumors adopted a p53-like phenotype after therapy. Our observations have important implications for prognostication, the future clinical development of targeted agents, and disease management with conventional chemotherapy.

miR-200 Expression Regulates Epithelial-to-Mesenchymal Transition in Bladder Cancer Cells and Reverses Resistance to Epidermal Growth Factor Receptor Therapy

Purpose: The epithelial-to-mesenchymal transition (EMT) is a cell development-regulated process in which noncoding RNAs act as crucial modulators. Recent studies have implied that EMT may contribute to resistance to epidermal growth factor receptor (EGFR)–directed therapy. The aims of this study were to determine the potential role of microRNAs (miRNA) in controlling EMT and the role of EMT in inducing the sensitivity of human bladder cancer cells to the inhibitory effects of the anti-EGFR therapy. Experimental Design: miRNA array screening and real-time reverse transcription-PCR were used to identify and validate the differential expression of miRNAs involved in EMT in nine bladder cancer cell lines. A list of potential miR-200 direct targets was identified through the TargetScan database. The precursor of miR-200b and miR-200c was expressed in UMUC3 and T24 cells using a retrovirus or a lentivirus construct, respectively. Protein expression and signaling pathway modulation, as well as intracellular distribution of EGFR and ERRFI-1, were validated through Western blot analysis and confocal microscopy, whereas ERRFI-1 direct target of miR-200 members was validated by using the wild-type and mutant 3′-untranslated region/ERRFI-1/luciferse reporters. Results: We identified a tight association between the expression of miRNAs of the miR-200 family, epithelial phenotype, and sensitivity to EGFR inhibitors–induced growth inhibition in bladder carcinoma cell lines. Stable expression of miR-200 in mesenchymal UMUC3 cells increased E-cadherin levels, decreased expression of ZEB1, ZEB2, ERRFI-1, and cell migration, and increased sensitivity to EGFR-blocking agents. The changes in EGFR sensitivity by silencing or forced expression of ERRFI-1 or by miR-200 expression have also been validated in additional cell lines, UMUC5 and T24. Finally, luciferase assays using 3′-untranslated region/ERRFI-1/luciferase and miR-200 cotransfections showed that the direct down-regulation of ERRFI-1 was miR-200-dependent because mutations in the two putative miR-200-binding sites have rescued the inhibitory effect. Conclusions: Members of the miR-200 family appear to control the EMT process and sensitivity to EGFR therapy in bladder cancer cells and the expression of miR-200 is sufficient to restore EGFR dependency at least in some of the mesenchymal bladder cancer cells. The targets of miR-200 include ERRFI-1, which is a novel regulator of EGFR-independent growth. (Clin Cancer Res 2009;15(16):5060–72)

Role of epithelial-to-mesenchymal transition (EMT) in drug sensitivity and metastasis in bladder cancer

Epithelial-to-mesenchymal transition (EMT) is a process that plays essential roles in development and wound healing that is characterized by loss of homotypic adhesion and cell polarity and increased invasion and migration. At the molecular level, EMT is characterized by loss of E-cadherin and increased expression of several transcriptional repressors of E-cadherin expression (Zeb-1, Zeb-2, Twist, Snail, and Slug). Early work established that loss of E-cadherin and increased expression of MMP-9 was associated with a poor clinical outcome in patients with urothelial tumors, suggesting that EMT might also be associated with bladder cancer progression and metastasis. More recently, we have used global gene expression profiling to characterize the molecular heterogeneity in human urothelial cancer cell lines (n = 20) and primary patient tumors, and unsupervised clustering analyses revealed that the cells naturally segregate into two discrete “epithelial” and “mesenchymal” subsets, the latter consisting entirely of muscle-invasive tumors. Importantly, sensitivity to inhibitors of the epidermal growth factor receptor (EGFR) or type-3 fibroblast growth factor receptor (FGFR3) was confined to the “epithelial” subset, and sensitivity to EGFR inhibitors could be reestablished by micro-RNA-mediated molecular reversal of EMT. The results suggest that EMT coordinately regulates drug resistance and muscle invasion/metastasis in urothelial cancer and is a dominant feature of overall cancer biology.

Micropapillary bladder cancer: a review of the University of Texas M. D. Anderson Cancer Center experience with 100 consecutive patients.

Micropapillary bladder carcinoma is a rare variant of urothelial carcinoma. To improve understanding of this disease, the authors performed a retrospective review of their experience.

Incidence of downstaging and complete remission after neoadjuvant chemotherapy for high‐risk upper tract transitional cell carcinoma

The authors evaluated the incidence of pathologic downstaging and complete remission (CR) in patients with high‐grade ureteral and renal pelvic transitional cell carcinoma (TCC) (upper tract TCC) who received neoadjuvant chemotherapy followed by surgery.

Partial Cystectomy for Muscle Invasive Urothelial Carcinoma of the Bladder: A Contemporary Review of the M. D. Anderson Cancer Center Experience

PURPOSE Partial cystectomy is a surgical option for select patients diagnosed with urothelial carcinoma. We review our experience with partial cystectomy for muscle invasive urothelial carcinoma to assess local control and survival rates. MATERIAL AND METHODS From 1982 to 2003 a total of 37 patients with muscle invasive urothelial carcinoma underwent partial cystectomy with curative intent. Reviewed data included history of superficial tumors, presence of variant histology, tumor location, clinical stage, pathological stage, presence of carcinoma in situ, adjuvant therapy and disease status. RESULTS The 5-year overall, disease specific and recurrence-free survival rates were 67%, 87% and 39%, respectively. Mean followup was 72.6 months (range 6 to 217). Of the 37 patients 19 (51%) did not have tumor recurrence, 9 (24%) had superficial recurrence in the bladder that was treated successfully and 9 (24%) had recurrence with advanced disease. A total of 24 patients (65%) had an intact bladder with no evidence of disease after a median of 53 months. There were 6 patients (16%) who died of bladder cancer, 3 of whom died of late recurrence of muscle invasive cancer (41, 44 and 138 months after partial cystectomy). On multivariate analysis higher pathological stage (HR 3.4, p = 0.04) was associated with shorter recurrence-free survival. A history of superficial tumors (p <0.01) and clinical stage (p = 0.01) was associated with advanced recurrence-free survival. The use of adjuvant chemotherapy (HR 0.18, p = 0.03) was associated with prolonged advanced recurrence-free survival, however adjuvant chemotherapy did not impact overall survival. CONCLUSIONS Partial cystectomy provides adequate local control of muscle invasive bladder cancer in select patients. Because late recurrence is not uncommon and is potentially life threatening, lifelong followup with cystoscopy is recommended.

ICUD-EAU International Consultation on Bladder Cancer 2012: Chemotherapy for Urothelial Carcinoma—Neoadjuvant and Adjuvant Settings

CONTEXT We present a summary of the Second International Consultation on Bladder Cancer recommendations on chemotherapy for the treatment of bladder cancer using an evidence-based strategy. OBJECTIVE To review the data regarding chemotherapy in patients with clinically localized and metastatic bladder cancer with a focus on its use for patients in the neoadjuvant and adjuvant settings. EVIDENCE ACQUISITION Medline databases were searched for original articles published prior to April 1, 2012, using the following search terms: bladder cancer, urothelial cancer, metastatic, advanced, neoadjuvant, and adjuvant therapy. Proceedings of major conferences from the last 5 yr also were searched. Novel and promising drugs currently in clinical trials were included. EVIDENCE SYNTHESIS The major findings are addressed in an evidence-based manner. Prospective trials and important cohort data were analyzed. CONCLUSIONS Cisplatin-based combination chemotherapy for advanced and metastatic bladder cancer is an established standard, improving overall survival. In the advanced setting, cisplatin-ineligible patients may benefit from gemcitabine and carboplatin. Meta-analyses undertaken for neoadjuvant cisplatin-based combination chemotherapy show a 5% benefit in overall survival. Pathologic complete remission may be an intermediate surrogate for survival, but requires further validation. Use of neoadjuvant chemotherapy is low, and is attributable to patient and physician choice because of limited benefit, advanced age, and comorbidities including renal and/or cardiac dysfunction. Sufficient data to support adjuvant chemotherapy are lacking.

Intrinsic basal and luminal subtypes of muscle-invasive bladder cancer

Whole-genome analyses have revealed that muscle-invasive bladder cancers (MIBCs) are heterogeneous and can be grouped into basal and luminal subtypes that are highly reminiscent of those found in breast cancer. Basal MIBCs are enriched with squamous and sarcomatoid features and are associated with advanced stage and metastatic disease at presentation. Like basal breast cancers, basal bladder tumours contain a claudin-low subtype that is enriched with biomarkers characteristic of epithelial-to-mesenchymal transition. The stem cell transcription factor ΔNp63α controls basal MIBC gene expression, just as it does in basal breast cancers. Luminal MIBCs are enriched with activating FGFR3 and ERBB3 mutations and ERBB2 amplifications, and their gene expression profiles are controlled by peroxisome proliferator activator receptor γ (PPARγ) and possibly also by oestrogen receptor activation. Luminal bladder cancers can be further subdivided into two subtypes, p53-like and luminal, which can be distinguished from one another by different levels of biomarkers that are characteristic of stromal infiltration, cell cycle progression, and proliferation. Importantly, basal bladder cancers are intrinsically aggressive, but are highly sensitive to cisplatin-based combination chemotherapy. Although the luminal subtypes are not as intrinsically aggressive as basal cancers, p53-like tumours are resistant to chemotherapy and might, therefore, represent a problem for treated patients.

Frequent truncating mutations of STAG2 in bladder cancer

Here we report the discovery of truncating mutations of the gene encoding the cohesin subunit STAG2, which regulates sister chromatid cohesion and segregation, in 36% of papillary non-invasive urothelial carcinomas and 16% of invasive urothelial carcinomas of the bladder. Our studies suggest that STAG2 has a role in controlling chromosome number but not the proliferation of bladder cancer cells. These findings identify STAG2 as one of the most commonly mutated genes in bladder cancer.

Phase II Clinical Trial of Neoadjuvant Alternating Doublet Chemotherapy With Ifosfamide/Doxorubicin and Etoposide/Cisplatin in Small-Cell Urothelial Cancer

PURPOSE Currently, treatment recommendations for small-cell urothelial cancer (SCUC) are based on anecdotal case reports and small retrospective series. We now report results from the first phase II clinical trial developed exclusively for SCUC, to our knowledge. PATIENTS AND METHODS From 2001 to 2006, 30 patients with SCUC provided consent and were treated with alternating doublet chemotherapy. Patients with surgically resectable disease (< or = cT4aN0M0) received a total of four cycles of neoadjuvant chemotherapy, whereas those with unresectable disease (> or = cT4b, N+, or M+) received two cycles beyond maximal response. RESULTS Eighteen patients with surgically resectable SCUC received neoadjuvant treatment with a median overall survival (OS) of 58 months; 13 of these patients remain alive and cancer free. For patients with cT2N0M0 SCUC, the 5-year OS rate is 80%; only one of four patients with cT3b-4aN0M0 remains alive (median OS, 37.8 months). For 12 patients with unresectable or metastatic SCUC, the median OS was 13.3 months. Chemotherapy was well tolerated, with transfusion, neutropenic fever, and infection remaining the most frequent grade 3 and 4 toxicities. There was only one postsurgical death. Brain metastases were strongly associated with more advanced-stage disease, developing in eight of 16 patients with either bulky tumors (> or = cT3b) or metastatic disease (P = .004). CONCLUSION These clinical trial results are consistent with previously reported retrospective data demonstrating long-term survival with four cycles of neoadjuvant chemotherapy for surgically resectable SCUC. Once metastases develop, the prognosis remains poor. The strong positive association between disease stage and brain metastases highlights a patient subset that may potentially benefit from prophylactic cranial irradiation.