Gastric adenocarcinoma expressing human epidermal growth factor receptor in South Asian population

A study of human epidermal growth factor receptor 2 overexpression by immunohistochemistry in patients with gastric adenocarcinoma

Gastric cancer is one of the leading causes of cancer-related deaths across the world and in the Middle East. Human epidermal growth factor receptor 2 (HER2) overexpression has been observed in gastric cancers. Trastuzumab, a recombinant monoclonal antibody targeting HER2 protein, is being used for treatment of metastatic gastric cancer. To study the frequency and association of HER2 overexpression with age, gender, histopathological subtype and grade of differentiation in patients with gastric adenocarcinoma from Basra, Iraq. This cross-sectional single-center study collected demographic (age, gender), histopathological (histological subtype, grade of differentiation) and immunohistochemical (HER2 overexpression status) data from 100 consenting adult patients (male: 56) with histopathologically confirmed gastric adenocarcinoma from samples obtained through endoscopy or surgery. HER2 overexpression (ToGA score 3+) was observed in 6/100 (6%) of patients, with another 6 showing 'equivocal' HER2 expression (2+). Out of 20 patients with moderately differentiated gastric cancer, 4 (20%) showed HER2 overexpression (p=0.008). Other factors considered (age, gender, histological subtype) did not show statistically significant correlation with HER2 overexpression. More females showed HER2 overexpression than males (4 vs. 2), and more patients with intestinal type gastric cancer showed HER2 overexpression than diffuse gastric cancer (5 vs. 1), but the difference was not statistically significant in both variables. HER2 overexpression was 6% in this population; statistically significant correlation was found with histological grade. Statistically non-significant correlations were observed between HER2 overexpression and gender, age, and histological subtype.

The Expression and Effect of ABCE1 in Gastric Adenocarcinoma

ATP-binding cassette E1 (ABCE1) is mainly related to the regulation of viral infection, cell multiplication, and anti-apoptosis. Previous reports confirmed the central role in the regulation of ABCE1 in liver and breast cancer; however, its potential role in gastric adenocarcinoma remains unclear. In our study, siRNA and plasmid were transfected to construct gastric cancer cell lines with low and overexpression of ABCE1, and Western blot, RT-qPCR, and immunohistochemical staining were used to detect ABCE1 expression levels in gastric cancer tissues and cell lines. The effects of ABCE1 on cell growth, metastasis, invasion, cell cycle, and drug resistance were investigated using CCK-8 test, wound healing assay, and clone formation experiment. Functional experiments indicated that si-ABCE1 decreased the proliferation, metastasis, and invasion of gastric adenocarcinoma. Meanwhile, si-ABCE1 has significantly promoted EMT process and enhanced the sensitivity of paclitaxel and cisplatin. In vivo experiments also confirmed that si-ABCE1 group had significantly smaller tumors, and immunohistochemical staining results showed the tumor growth in si-ABCE1 group was reduced obviously. In summary, we found ABCE1 is considered as a crucial role in the evolution of gastric adenocarcinoma and could be a viable therapeutic target for the disease.

Recent Advances in Systemic Treatments for HER-2 Positive Advanced Gastric Cancer

Gastric cancer (GC) is the fifth most common cancer worldwide. Despite recent improvements in treatment quality and options, advanced gastric cancer remains one of the hardest to cure cancers, with a median overall survival (OS) of 10–12 months and a 5-year OS of approximately 5–20%. There is an unmet need for further efforts to palliate disease-related symptoms, improve quality of life, increase tumor response rate, and prolong progression free and overall survival while balancing the toxicities of therapy. The most common type of GC is adenocarcinoma, which demonstrates morphological, biological, and clinical heterogeneity. A plethora of genomic alterations and the activation of numerous molecular pathways including human epidermal growth receptor 2 (HER2), epidermal growth factor receptor (EGFR), fibroblast growth factor receptor-2 (FGFR2), mesenchymal epidermal transforming factor receptor (MET), and the phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) are responsible for the complex heterogeneity of GC. Efforts to validate the therapeutic effects of inhibiting some of these aberrantly expressed pathways have failed to lead to a clinically meaningful outcome apart from the overexpression/amplification of the HER2 gene, inhibition of which has had a significant impact on clinical practice. The only available biomarkers to guide the effective treatment of patients with advanced GC are HER2 overexpression, MSI/PD-L1 status, and FGFR alterations. Various anti-HER2 agents have been evaluated after the success of the ToGA trial, but none led to a significant enough clinical improvement to be considered a viable alternative for HER2-targeted therapy in advanced GC until the global Keynote-811 trial, which added pembrolizumab to trastuzumab in combination with chemotherapy. This combination demonstrated a survival advantage for the first time in the 11 years since ToGA. Trastuzumab deruxtecan (T-DXd) was also found to be effective in patients who had already received >2 previous lines of treatment. Despite these promising avenues, the optimal management of HER-2 positive GC still requires further development.

Contrast-Enhanced CT Parameters of Gastric Adenocarcinoma: Can Radiomic Features Be Surrogate Biomarkers for HER2 Over-Expression Status?

Objective

The aim of this study was to determine the role of contrast-enhanced computed tomography (CE-CT) parameters in predicting the expression status of HER2 in gastric adenocarcinoma (GAC) patients before radical gastrectomy.

Materials and Methods

A total of 460 GAC patients who underwent non-contrast CT (NC-CT) and CE-CT examinations before radical resection were enrolled in this retrospective study. The radiologists reviewed their CT scans and recorded parameters, including CT attenuate value (CAV) and corrected CAV (cCAV). The pathologist identified the postoperative HER2 expression status, and HER2 expression status was evaluated by immunohistochemical staining (IHC). The association between CE-CT parameters and HER2 expression status was analyzed.

Results

Among the 460 patients, 84 patients had HER2 over-expression status, at a prevalence of 18.3%. The CAVs were significantly different between the 2 different HER2 expression groups in the non-contrast and arterial phases (non-contrast phase: p = 0.005; arterial phase: p < 0.001). Besides, there was a significant difference in the cCAVs between the 2 groups in the arterial phase (arterial phase: p = 0.003). Univariate and multivariate logistic regression analyses identified that the maximum diameter of tumor, differentiation degree, CAV in non-contrast, arterial, and portal phases, and cCAV in the arterial phase were predictive factors of HER2 expression status.

Conclusion

Our analyses showed that the CE-CT parameters were significantly different between different HER2 expression groups. CE-CT parameters could serve as simple, objective predictive factors of HER2 expression status of GAC patients.

Prevalence of HER2 Expression and Its Correlation with Clinicopathological Parameters in Gastric or Gastroesophageal Junction Adenocarcinoma in North-East Indian Population

Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicated in advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2 positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-East India and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of 68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examination from September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational (epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved, standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters. Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantly higher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patients with well differentiated histology and was more common in patients with stage II and III diseases, but neither of the associations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours (56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patients with locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlated significantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expression is recommended to provide a therapeutic advantage in Indian patients.