HER2 testing in gastric cancer: An update

Area of Science:

• Oncology
• Molecular Diagnostics
• Gastroenterology

Background:

• Human epidermal growth factor receptor 2 (HER2) overexpression is a frequent molecular abnormality in gastric and gastroesophageal cancers.
• Targeted therapy for HER2-positive advanced gastric cancer necessitates accurate HER2 status determination.
• Understanding HER2's role is critical for patient selection and treatment efficacy.

Purpose of the Study:

• To provide an update on the knowledge of HER2 in gastric and gastroesophageal cancer.
• To discuss the prognostic relevance of HER2 in these cancers.
• To highlight differences in HER2 interpretation between breast and gastric cancer.

Main Methods:

• Review of current literature and clinical guidelines.
• Analysis of HER2 detection methods, including immunohistochemistry (IHC).
• Discussion of the standardized IHC scoring system for gastric cancer.

Main Results:

• HER2 status is a key predictive biomarker for targeted therapy in advanced gastric cancer.
• Interpretation of HER2 protein expression differs significantly between breast and gastric cancer.
• Standardized detection and scoring are essential for reliable HER2 assessment.

Conclusions:

• Accurate HER2 testing is crucial for guiding HER2-targeted therapy in gastric and gastroesophageal cancer.
• Awareness of specific interpretation criteria for gastric cancer is necessary.
• This review consolidates current understanding to aid clinical decision-making.