Clinical Significance of ErbB Receptor Family in Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-Analysis

Evaluation of molecular signatures in the urinary bladder and upper tract urothelial carcinomas: a prospective controlled clinical study

Background

Urothelial carcinomas (UC) can be either in the upper or in the lower urinary tract or both. Urothelial bladder cancer (UBC) is more common than upper tract urothelial carcinoma (UTUC). This research was designed to study the difference between UBC and UTUC using the molecular pathways including (MAPK/ERK) pathway, cell cycle regulating genes, and oncogenic genes.

Methods

To study the discrepancy between UBC and UTUC, a prospective trial was carried out for 31 radical cystectomy and 19 nephrouretrectomy fresh-frozen specimens of UBC and UTUC patients, respectively. The expression level of mRNA of eight genes namely EGFR, ELK1, c-fos, survivin, TP53, RB1, FGFR3, and hTERT was assessed in normal adjacent tissues, UTUC, and UBC by RT-PCR.

Results

Comparison between UTUC and UBC regarding the expression level of mRNA of the EGFR, ELK1, c-fos, survivin, TP53, and FGFR3 had significant difference (p-value < 0.001), while the expression level of RB1 and hTERT level had no significance. Sensitivity/specificity of EGFR, Elk1, c-fos, survivin, TP53, and FGFR3 was 0.78/0.90, 0.84/0.90, 0.84/0.80, 0.84/0.96, 0.94/0.93, and 0.89/0.93, respectively, to differentiate between UTUC and UBC.

Conclusions

Despite the fact that UTUC and UBC share the same origin, there is a clear evidence that there is a molecular difference between them. This molecular difference could be the reason that UTUC is more aggressive than UBC.

Lapatinib as first-line treatment for muscle-invasive urothelial carcinoma in dogs

Epidermal growth factor receptors 1 and 2 (EGFR and HER2) are frequently overexpressed in various malignancies. Lapatinib is a dual tyrosine kinase inhibitor that inhibits both EGFR and HER2. Although a phase III trial failed to show the survival benefits of lapatinib treatment after first-line chemotherapy in patients with EGFR/HER2-positive metastatic urothelial carcinoma, the efficacy of lapatinib for untreated urothelial carcinoma is not well defined. Here, we describe the therapeutic efficacy of lapatinib as a first-line treatment in a canine model of muscle-invasive urothelial carcinoma. In this non-randomized clinical trial, we compared 44 dogs with naturally occurring urothelial carcinoma who received lapatinib and piroxicam, with 42 age-, sex-, and tumor stage-matched dogs that received piroxicam alone. Compared to the dogs treated with piroxicam alone, those administered the lapatinib/piroxicam treatment had a greater reduction in the size of the primary tumor and improved survival. Exploratory analyses showed that HER2 overexpression was associated with response and survival in dogs treated with lapatinib. Our study suggests that lapatinib showed encouraging durable response rates, survival, and tolerability, supporting its therapeutic use for untreated advanced urothelial carcinoma in dogs. The use of lapatinib as a first-line treatment may be investigated further in human patients with urothelial carcinoma.

A Review of HER4 (ErbB4) Kinase, Its Impact on Cancer, and Its Inhibitors

HER4 is a receptor tyrosine kinase that is required for the evolution of normal body systems such as cardiovascular, nervous, and endocrine systems, especially the mammary glands. It is activated through ligand binding and activates MAPKs and PI3K/AKT pathways. HER4 is commonly expressed in many human tissues, both adult and fetal. It is important to understand the role of HER4 in the treatment of many disorders. Many studies were also conducted on the role of HER4 in tumors and its tumor suppressor function. Mostly, overexpression of HER4 kinase results in cancer development. In the present article, we reviewed the structure, location, ligands, physiological functions of HER4, and its relationship to different cancer types. HER4 inhibitors reported mainly from 2016 to the present were reviewed as well.

EMP1, EMP 2, and EMP3 as novel therapeutic targets in human cancer

The epithelial membrane protein genes 1, 2, and 3 (EMP1, EMP2, and EMP3) belong to the peripheral myelin protein 22-kDa (PMP22) gene family, which consists of at least seven members: PMP22, EMP1, EMP2, EMP3, PERP, brain cell membrane protein 1, and MP20. This review addresses the structural and functional features of EMPs, detailing their tissue distribution and functions in the human body, their expression pattern in a variety of tumors, and highlighting the underlying mechanisms involved in carcinogenesis. The implications in cancer biology, patient prognosis prediction, and potential application in disease therapy are discussed. For example, EMP1 was reported to be a biomarker of gefitinib resistance in lung cancer and contributes to prednisolone resistance in acute lymphoblastic leukemia patients. EMP2 functions as an oncogene in human endometrial and ovarian cancers; however, characteristics of EMP2 in urothelial cancer fulfill the criteria of a suppressor gene. Of particular interest, EMP3 overexpression in breast cancer is significantly related to strong HER-2 expression. Co-expression of HER-2 and EMP3 is the most important indicator of progression-free and metastasis-free survival for patients with urothelial carcinoma of the upper urinary tract. Altogether, discovery of pharmacological inhibitors and/or regulators of EMP protein activity could open novel strategies for enhanced therapy against EMP-mediated human diseases.

Phase III, Double-Blind, Randomized Trial That Compared Maintenance Lapatinib Versus Placebo After First-Line Chemotherapy in Patients With Human Epidermal Growth Factor Receptor 1/2-Positive Metastatic Bladder Cancer

Purpose To establish whether maintenance lapatinib after first-line chemotherapy is beneficial in human epidermal growth factor receptor (HER) 1/HER2-positive metastatic urothelial bladder cancer (UBC). Methods Patients with metastatic UBC were screened centrally for HER1/HER2 overexpression. Patients who screened positive for HER1/2 and who did not have progressive disease during chemotherapy (four to eight cycles) were randomly assigned one to one to lapatinib or placebo after completion of first-line/initial chemotherapy for metastatic disease. The primary end point was progression-free survival (PFS). Results Between 2007 and 2013, 446 patients with UBC were screened, and 232 with HER1- or HER2-positive disease were randomly assigned. The median PFS for lapatinib and placebo was 4.5 (95% CI, 2.8 to 5.4) and 5.1 (95% CI, 3.0 to 5.8) months, respectively (hazard ratio, 1.07; 95% CI, 0.81 to 1.43; P = .63). The overall survival for lapatinib and placebo was 12.6 (95% CI, 9.0 to 16.2) and 12.0 (95% CI, 10.5 to 14.9) months, respectively (hazard ratio, 0.96; 95% CI, 0.70 to 1.31; P = .80). Discontinuation due to adverse events were similar in both arms (6% lapatinib and 5% placebo). The rate of grade 3 to 4 adverse events for lapatinib and placebo was 8.6% versus 8.1% ( P = .82). Preplanned subset analysis of patients strongly positive for HER1/HER2 (3+ on immunohistochemistry; n = 111), patients positive for only HER1 (n = 102), and patients positive for only HER2 (n = 42) showed no significant benefit with lapatinib in terms of PFS and overall survival ( P > .05 for each). Conclusion This trial did not find significant improvements in outcome by the addition of maintenance lapatinib to standard of care.

Comprehensive genomic profiling of 295 cases of clinically advanced urothelial carcinoma of the urinary bladder reveals a high frequency of clinically relevant genomic alterations

BACKGROUND

In the current study, the authors present a comprehensive genomic profile (CGP)-based study of advanced urothelial carcinoma (UC) designed to detect clinically relevant genomic alterations (CRGAs).

METHODS

DNA was extracted from 40 µm of formalin-fixed, paraffin-embedded sections from 295 consecutive cases of recurrent/metastatic UC. CGP was performed on hybridization-captured, adaptor ligation-based libraries to a mean coverage depth of 688X for all coding exons of 236 cancer-related genes plus 47 introns from 19 genes frequently rearranged in cancer, using process-matched normal control samples as a reference. CRGAs were defined as GAs linked to drugs on the market or currently under evaluation in mechanism-driven clinical trials.

RESULTS

All 295 patients assessed were classified with high-grade (International Society of Urological Pathology classification) and advanced stage (stage III/IV American Joint Committee on Cancer) disease, and 294 of 295 patients (99.7%) had at least 1 GA on CGP with a mean of 6.4 GAs per UC (61% substitutions/insertions/deletions, 37% copy number alterations, and 2% fusions). Furthermore, 275 patients (93%) had at least 1 CRGA involving 75 individual genes with a mean of 2.6 CRGAs per UC. The most common CRGAs involved cyclin-dependent kinase inhibitor 2A (CDKN2A) (34%), fibroblast growth factor receptor 3 (FGFR3) (21%), phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) (20%), and ERBB2 (17%). FGFR3 GAs were diverse types and included 10% fusions. ERBB2 GAs were equally divided between amplifications and substitutions. ERBB2 substitutions were predominantly within the extracellular domain and were highly enriched in patients with micropapillary UC (38% of 32 cases vs 5% of 263 nonmicropapillary UC cases; P<.0001).

CONCLUSIONS

Using a CGP assay capable of detecting all classes of GA simultaneously, an extraordinarily high frequency of CRGA was identified in a large series of patients with advanced UC. Cancer 2016;122:702-711. © 2015 American Cancer Society.

Muscle-invasive urothelial bladder cancer: an update on systemic therapy

Urothelial carcinoma is a common malignancy that carries a poor prognosis when the disease includes muscle invasion. Metastatic urothelial carcinoma is almost uniformly fatal. The evidence behind treatment options in the neoadjuvant, adjuvant and metastatic settings are discussed in this manuscript, with a focused review of standard and investigational cytotoxic, targeted, and immunotherapy approaches. We have focused especially on neoadjuvant cisplatin-based therapy (supported by level one evidence) and on novel immunotherapy agents such as checkpoint inhibitors, which have shown great promise in early clinical studies.

The c-MET Network as Novel Prognostic Marker for Predicting Bladder Cancer Patients with an Increased Risk of Developing Aggressive Disease

Previous studies have shown that c-MET is overexpressed in cases of aggressive bladder cancer (BCa). Identification of crosstalk between c-MET and other RTKs such as AXL and PDGFR suggest that c-MET network genes (c-MET-AXL-PDGFR) may be clinically relevant to BCa. Here, we examine whether expression of c-MET network genes can be used to identify BCa patients at increased risk of developing aggressive disease. In vitro analysis, c-MET knockdown suppressed cell proliferation, invasion, and migration, and increased sensitivity to cisplatin-induced apoptosis. In addition, c-MET network gene (c-MET, AXL, and PDGFR) expression allowed discrimination of BCa tissues from normal control tissues and appeared to predict poor disease progression in non-muscle invasive BCa patients and poor overall survival in muscle invasive BCa patients. These results suggest that c-MET network gene expression is a novel prognostic marker for predicting which BCa patients have an increased risk of developing aggressive disease. These genes might be a useful marker for co-targeting therapy, and are expected to play an important role in improving both response to treatment and survival of BCa patients.

Emerging therapeutic targets in bladder cancer

Treatment of muscle invasive urothelial bladder carcinoma (BCa) remains a major challenge. Comprehensive genomic profiling of tumors and identification of driver mutations may reveal new therapeutic targets. This manuscript discusses relevant molecular drivers of the malignant phenotype and agents with therapeutic potential in BCa. Small molecule pan-FGFR inhibitors have shown encouraging efficacy and safety results especially among patients with activating FGFR mutations or translocations. mTOR inhibitors for patients with TSC1 mutations and concomitant targeting of PI3K and MEK represent strategies to block PI3K/AKT/mTOR pathway. Encouraging preclinical results with ado-trastuzumab emtansine (T-DM1) exemplifies a new potential treatment for HER2-positive BCa along with innovative bispecific antibodies. Inhibitors of cell cycle regulators (aurora kinase, polo-like kinase 1, and cyclin-dependent kinase 4) are being investigated in combination with chemotherapy. Early results of clinical studies with anti-CTLA4 and anti-PDL1 are propelling immune modulating drugs to the forefront of emerging treatments for BCa. Collectively, these novel therapeutic targets and treatment strategies hold promise to improve the outcome of patients afflicted with this malignancy.

A randomized phase 2 trial of gemcitabine/cisplatin with or without cetuximab in patients with advanced urothelial carcinoma

BACKGROUND

Epidermal growth factor receptor overexpression is associated with poor outcomes in urothelial carcinoma (UC). Cetuximab (CTX) exhibited an antitumor effect in in vivo UC models. The efficacy of gemcitabine/cisplatin (GC) with or without CTX in patients with advanced UC was evaluated.

METHODS

Patients with advanced UC, measurable disease, and adequate organ function were randomized 1:2 to cisplatin (70 mg/m(2) ) on day 1 plus gemcitabine (1000 mg/m(2) ) on days 1, 8, and 15 (arm A) or GC plus CTX (500 mg/m(2) ) on days 1 and 15 (arm B). The primary endpoint was the overall response rate. The secondary endpoints were the response duration, safety, progression-free survival, overall survival, determination of whether or not CTX sensitized nonresponders to GC, and exploratory biomarker analysis. The accrual targets were 27 and 54 patients for the 2 arms, respectively. The overall response rate was reported by arm with binomial confidence intervals (CIs). Kaplan-Meier methods were used for time-to-event endpoints.

RESULTS

Eighty-eight eligible patients were randomized; 87 were toxicity-evaluable, and 85 were response-evaluable. The overall response rates were 57.1% for arm A (95% CI = 37%-76%) and 61.4% for arm B (95% CI = 48%-74%). The median progression-free survival times were 8.5 months for arm A (95% CI = 5.7-10.4 months) and 7.6 months for arm B (95% CI = 6.1-8.7 months). The median overall survival times were 17.4 months for arm A (95% CI = 12.8 months to unreached) and 14.3 months for arm B (95% CI = 11.6-22.2 months). The most common grade 3/grade 4 adverse events in both arms were myelosuppression and nausea. Thromboembolism, acneiform rash, fatigue, pain, hypersensitivity reactions, elevated transaminases, hyponatremia, and hypomagnesemia were more common in arm B; 3 grade 5 adverse events occurred in arm B. The presence of primary disease significantly correlated with thromboembolism. An increased soluble E-cadherin level after cycle 2 correlated with a higher risk of death.

CONCLUSIONS

GC plus CTX was feasible but was associated with more adverse events and no improvements in outcomes.

Evaluation of the antitumor activity of dacomitinib in models of human bladder cancer

Members of the human epidermal growth factor receptor (HER) family play a significant role in bladder cancer progression and may underlie the development of chemotherapy resistance. Dacomitinib is an irreversible tyrosine kinase inhibitor with structural specificity for the catalytic domains of epidermal growth factor receptor (EGFR), HER2 and HER4 that has exhibited vigorous efficacy against other solid tumors. We evaluated the antitumor activity of dacomitinib in human bladder cancer cell lines expressing varying levels of HER family receptors. These cell lines also were established as bladder cancer xenografts in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice to assess dacomitinib activity in vivo. Significant cytotoxic and cytostatic effects were noted in cells expressing elevated levels of the dacomitinib target receptors with apoptosis and cell cycle arrest being the predominant mechanisms of antitumor activity. Cells expressing lower levels of HER receptors were much less sensitive to dacomitinib. Interestingly, dacomitinib was more active than either trastuzumab or cetuximab in vitro, and exhibited increased growth inhibition of bladder tumor xenografts compared with lapatinib. Pharmacodynamic effects of dacomitinib included decreased E-cadherin (E-cad) expression, reduction of EGFR and extracellular signal-regulated kinase (ERK) phosphorylation and reduced mitotic count. Dacomitinib also inhibited tumor growth in a chemotherapy-resistant xenograft and, when combined with chemotherapy in a sensitive xenograft, exhibited superior antitumor effects compared with individual treatments. Evaluation in xenograft-bearing mice revealed that this combination was broadly feasible and well tolerated. In conclusion, dacomitinib exhibited pronounced activity both as a single agent and when combined with chemotherapy in human bladder cancer models. Further investigation of dacomitinib in the preclinical and clinical trial settings is being pursued.