Comprehensive Overview of Gastric Cancer Immunohistochemistry: Key Biomarkers, Advanced Detection Methods, and...

Area of Science:

• Oncology
• Pathology
• Molecular Diagnostics

Background:

• Immunohistochemistry (IHC) is essential for managing gastric cancer (GC), enabling personalized treatment strategies for advanced and metastatic cases.
• Accurate molecular subclassification and predicting treatment response are critical challenges in GC management.

Purpose of the Study:

• To review the critical role of IHC markers in GC management.
• To analyze IHC efficiency in molecular subclassification and predicting response to targeted therapies.
• To describe state-of-the-art IHC techniques and future perspectives in GC.

Main Methods:

• Review of current paradigms in gastric neoplasia diagnosis, including methodological, morphological, epidemiological, and differential diagnostic aspects.
• Analysis of advancements in 3,3'-diaminobenzidine (DAB) application and reagents for GC immunohistochemistry.
• Discussion of key biomarkers (HER2, PD-L1, MMR), differentiation markers, epithelial-mesenchymal transition, and innovative IHC procedures.

Main Results:

• Key IHC biomarkers (HER2, PD-L1, MMR) correlate tissue morphology with protein expression, aiding diagnosis and treatment selection.
• Intestinal/gastrointestinal differentiation markers, aggressive subtypes, and epithelial-mesenchymal transition provide insights into GC biology.
• Innovative IHC procedures, automation, and quality control enhance diagnostic accuracy and laboratory efficiency.

Conclusions:

• Despite limitations, IHC is indispensable in modern gastric oncology for personalized treatment.
• Digital pathology integration and refined scoring criteria will elevate IHC's role from a complementary test to a vital visual tool for treatment personalization.