HER2 positivity in gastric and esophageal adenocarcinoma: clinicopathological analysis and comparison

Abstract

HER2 positivity occurs in 15.6 % of invasive gastroesophageal adenocarcinoma in Western patients, of which the majority is esophageal primary tumors and of the intestinal tumor type. With the introduction of the 7th TNM edition, a large number of tumors previously classified as gastric are now classified as esophageal tumors instead, with relatively high HER2 positivity rates in these esophageal primary tumors.

Trastuzumab in the management of gastroesophageal cancer: patient selection and perspectives

“…The reported frequency of HER2 overexpression in GE cancer varies widely in the literature, ranging from 4% to >50% in some reports 26–29. The lowest frequency is reported in distal tumors and the highest in tumors of the GEJ 28,29. Rates of HER2 expression in squamous cell cancers of the upper esophagus are low, and as a result, the application of HER2-targeted therapy has generally been limited to adenocarcinomas of the lower esophagus and stomach 30.…”

“…Rates of HER2 expression in squamous cell cancers of the upper esophagus are low, and as a result, the application of HER2-targeted therapy has generally been limited to adenocarcinomas of the lower esophagus and stomach 30. An association with intestinal histology has been consistently reported, with HER2 amplification uncommon in diffuse gastric cancers 28. A recent case series of 1461 Japanese patients reported an HER2 positivity rate of 21%.…”

Cost-effectiveness of precision medicine in gastrointestinal stromal tumor and gastric adenocarcinoma

“…Through the use of precision medicine-associated diagnostic testing, 7-22% of GA have been found to overexpress the human epidermal receptor 2 (HER2), a prerequisite for the use and beneficial effect of the HER2 targeting agent, trastuzumab (6)(7)(8)(9)(10)(11). Based upon these initial studies and other early phase studies, a phase III trial was conducted to evaluate trastuzumab in HER2 positive (HER2+) metastatic GA (mGA).…”

New Strategies in Esophageal Carcinoma: Translational Insights from Signaling Pathways and Immune Checkpoints

“…Currently, the only validated therapeutic target for this disease is HER2, which is overexpressed in approximately 7% to 22% of gastroesophageal cancers, depending on the case series (18,20), and informs use of trastuzumab. Meanwhile, discovery of blood-or tumor-based biomarkers that predict sensitivity to inhibitors of VEGF/VEGFR signaling remains elusive.…”