Standardized and quality-assured predictive PD-L1 testing in the upper gastrointestinal tract

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Increasing complexity in treating esophageal, gastroesophageal junction, and stomach cancers due to immuno-oncology advancements.
• Treatment decisions for PD-1 inhibitors often rely on programmed cell death-ligand 1 (PD-L1) expression, necessitating accurate biomarker evaluation.

Purpose of the Study:

• To address challenges in the clinical diagnostic work of PD-L1 testing for upper gastrointestinal carcinomas.
• To develop recommendations for standardized implementation, quality assurance, and interpretation of PD-L1 testing.

Main Methods:

• An interdisciplinary expert group convened to discuss practical questions in pathological and clinical practice.
• Focus on crucial aspects including starting material, quality-assured testing, and interpretation of pathological findings.

Main Results:

• Identified challenges in the daily clinical diagnostic work related to PD-L1 testing due to tumor heterogeneity.
• Developed expert recommendations for structured reporting of PD-L1 expression in upper gastrointestinal cancers.

Conclusions:

• Standardized and reliable PD-L1 testing is essential for effective immuno-oncology treatment stratification in upper gastrointestinal cancers.
• Recommendations aim to improve consistency and accuracy in pathological assessment, aiding clinical decision-making.