Human epidermal growth factor receptor 2 (HER2) gene amplification in non-muscle invasive urothelial bladder cancers: Identification of patients for targeted therapy

Human epidermal growth factor receptor 2/neu expression in urothelial carcinomas

Introduction

Urothelial carcinomas of the bladder are more common in males, making them the sixth-most common cancer in men and the tenth-most common cancer overall, worldwide. Current guidelines do not recommend routine testing for human epidermal growth factor receptor (HER2/neu) expression on the biopsy specimens of patients with urothelial carcinoma. This study was aimed at determining the expression pattern of HER2/neu and its usefulness in muscle-invasive and nonmuscle-invasive urothelial carcinoma.

Methods

HER2/neu expression was assessed in 89 specimens of urothelial cancer by immunohistochemistry (IHC), and equivocal cases were subjected to fluorescent in situ hybridization (FISH).

Results

On IHC for HER2/neu, 17.9% (7/39) of the muscle-invasive bladder cancers (MIBCs) showed a 3+ expression, whereas 22% (11/50) of the non-muscle invasive cancers were positive with a score of 3+. A significant correlation between HER2/neu status and muscle invasion could not be established in the current study (P = 0.74, Fisher's exact test). Three cases of muscle-invasive (7.7%) and 2 cases (4%) among nonmuscle invasive cancers showed equivocal expression. All the cases with equivocal (2+) expression on IHC were subjected to FISH and none showed gene amplification on hybridization and were considered as negative.

Conclusion

Overexpression of HER-2/neu was seen in 17.9% of MIBCs and 22% of non-MIBCs. There are no norms for routine testing of HER2/neu expression in the biopsy specimens of urothelial carcinoma. There is an unmet need to establish guidelines for HER2/neu scoring, similar to that for breast and gastric cancers, to determine the proportion of positive cases and help in identification of those who may benefit from targeted therapies.

Advances in HER2-Targeted Treatment for Advanced/Metastatic Urothelial Carcinoma

Urothelial carcinoma (UC) represents a common malignancy of the urinary system that can involve the kidneys, ureter, bladder, and urethra. Advanced/metastatic UC (mUC) tends to have a poor prognosis. UC ranks third in terms of human epidermal growth factor receptor 2 (HER2) overexpression among all tumors. However, multiple studies found that, unlike breast cancer, variable degrees of HER2 positivity and poor consistency between HER2 protein overexpression and gene amplification have been found. Trials involving trastuzumab, pertuzumab, lapatinib, afatinib, and neratinib have failed to prove their beneficial effect in patients with HER2-positive mUC, and a clinical trial on T-DM1 (trastuzumab emtansine) was terminated prematurely because of the adverse reactions. However, a phase II trial showed that RC48-ADC was effective. In this review, we provided an in-depth overview of the advances in the research regarding HER2-targeted therapy and the role of HER2 in mUC. Furthermore, we also discussed the prospects of potential strategies aimed at overcoming anti-HER2 resistance, and summarize the novel anti-HER2 approaches for the management of mUC used in recent clinical trials.

Proteomics strategies for urothelial bladder cancer diagnosis, prognosis and treatment: Trends for tumor biomarker sources

Urothelial bladder cancer (UBC) is a heterogeneous multifactorial malignancy with a high recurrence rate. Current procedures for UBC diagnosis suffering from the lack of clinical sensitivity and specificity screening tests. Therefore, biomarkers have promising values to predict pathological conditions and can be considered as effective targets for early diagnosis, prognosis and antitumor immunotherapy. Recently, researchers have been interested for tumor proteins as biomarkers for different diseases. At present, proteomics methods have rapidly progressive that has potential identified biomarkers of UBC. Specifically, there has been several studies on the potential application of proteomics for the identification, quantification, and profiling of proteins for UBC in different sources. Based on these studies, using the panel of biomarkers as proteomic patterns may achieve higher sensitivity and specificity than single proteins in the diagnosis of UBC. In the present review, we evaluate recent literature related to the UBC proteome focusing especially on new proteomics techniques. Moreover, we classify UBC tumor biomarkers as diagnostic, prognostic, and therapeutic targets based on their sources (urine, serum/plasm, cell line, and tumor tissue) and we also discuss the advantages and limitations of each source. In this manner, this review article provides a critical assessment presentation of the advances in proteomics for all aspects of UBC diagnosis, prognosis, and treatment based on sources.

Expression of epidermal growth factor receptor and human epidermal growth factor receptor 2 in urothelial bladder carcinoma in an Egyptian cohort: Clinical implication and prognostic significance

BACKGROUND

Bladder cancer (BC) has a particular importance in Egyptian patients due to aggressive behavior and absence of prognostic markers.

OBJECTIVE

To evaluate the expression of gene and protein expression of HER2 and epidermal growth factor (EGFR) in Egyptian patients with BC and ultimately to investigate their clinical implication and prognostic significance.

MATERIAL AND METHODS

The study was carried out on 46 patients with urothelial bladder BC. Tissue were obtained from transurethral resection (N = 22) and radical cystectomy (N = 24) specimens. The original hematoxylin and eosin slides were re-evaluated and the formalin fixed, paraffin-embedded (FFPE) tissues which had sufficient tumor tissue (>75%) and minimal or absent tumor necrosis were selected for immunohistochemistry (IHC) and RNA extraction. Furthermore, five control biopsies were obtained from patients with cystitis. Follow-up data were retrieved from the medical records which included the treatment regimen, disease recurrence and/or progression, and survival.

RESULTS

EGFR and HER2 protein were overexpressed in 35% and 46% of patients respectively. EGFR was correlated with the tumor size, grade and pathological stage, with a similar trend for HER2. The recurrence rate was higher in patients with expression of any of the markers. Gene expression was significantly higher (10.6-folds) for EGFR and (21-folds) for HER2 in patients with BC in comparison to control patients. Survival analysis showed lower median disease-free survival in association with HER2 protein overexpression.

CONCLUSIONS

Our data highlighted the prognostic significance of EGFR and HER in BC and proposed their possible use as predictive markers and potential therapeutic targets.

Interaction between HER2 and ATM predicts poor survival in bladder cancer patients

Human Epidermal Growth Factor Receptor 2 (HER2) overexpression is considered one of the interesting prognostic biomarkers in bladder cancer. However, the mechanism of bladder cancer development in relation to HER2 status remains to be elucidated. In this study, we investigated HER2‐Ataxia telangiectasia mutated (ATM) kinase interaction and their impact on patient survival and cancer aggressiveness. Using the Cancer Genome Atlas (TCGA) cohorts, we demonstrated that ATM expression (protein/mRNA) is increased in HER2 deficient compared with proficient HER2 patients. This finding was then validated using the Gene Expression Omnibus database (GEO). Correlation analysis (using low expression vs high expression as a discriminator) revealed a significant association of ATM low and HER2 high status with several clinicopathological variables such as high tumour grade, late disease stage and tumour shape. Kaplan–Meier survival analysis indicated that ATM low and HER2 high is a powerful prognosticator of both overall survival (OS) and disease‐free survival (DFS). Furthermore, using bioinformatics and protein/protein interaction analyses, we identified 66 putative overlapping proteins with direct link between HER2 and ATM most of which are functionally involved in transcription regulation, apoptotic process and cell proliferation. Interestingly, the results showed that these proteins are strongly linked with PI3K‐Akt pathway, p53 pathway and microRNAs in cancer. Altogether, our data pinpoint an important biological role of the interconnection between HER2 and ATM. The latter appear to be an independent prognostic biomarker and may serve as targets to develop novel combination therapies to improve the outcome of patients with bladder cancer.

Overexpression of Her-2 in Biopsy-Proven Urothelial Carcinoma Patients From Pakistan

Background 

Bladder cancer is a common urological cancer. Her-2 gene is a proto-oncogene which is present in 17q12 chromosomal region. Her-2 overexpression has been seen in breast, gastric and ovarian cancers. The purpose of this study was to evaluate the incidence of overexpression of Her-2 in patients with urothelial carcinoma diagnosed by histopathology in the Pakistani population.

Methods

This is a cross-sectional observational study conducted on the biopsy samples of patients diagnosed with urothelial carcinoma in Histopathology Department of Chughtai Institute of Pathology from 15 September 2018 to 15 March 2021. The immunohistochemical analysis was done on serial sections using immune-enzymatic soluble complex method. The antibody used was Her-2 polyclonal antibodies from DAKO (Agilent, Santa Clara, USA). Her-2 scoring was done according to the College of American Pathologists (CAP) guidelines for reporting Her-2 overexpression in breast cancer.

Results

A total of 140 cases of urothelial cancer were included in the study. About 83.57% (n=117) of cases were males, and 16.42% (n=23) were females. Positive Her-2 staining was observed in 38/140 (27.15%) cases. A significant association was seen between Her-2 staining and muscle invasion (p-value=0.0001).

Conclusion

Our study shows that Her-2 overexpression is seen in a number of patients with urothelial carcinoma, especially in patients with muscle invasion. These patients may benefit from targeted therapy against the Her-2 gene. Her-2 overexpression evaluation should be considered in such patients.