Residual Tumor Resection After Anti-PD-1 Therapy: A Promising Treatment Strategy for Overcoming Immune Evasive...

Area of Science:

• Oncology
• Immunotherapy
• Gastrointestinal Cancer Research

Background:

• Anti-programmed death 1 receptor (PD-1) therapy shows promise for unresectable advanced or recurrent gastric/gastroesophageal junction (G/GEJ) cancer.
• Limited response rates and survival benefits necessitate further investigation into treatment efficacy and tumor immunology.

Purpose of the Study:

• To evaluate the clinical efficacy of tumor resection (TR) post-chemotherapy or anti-PD-1 therapy in G/GEJ cancer.
• To analyze the immune status of the tumor microenvironment (TME) after these treatments.

Main Methods:

• Retrospective analysis of patients with unresectable advanced or recurrent G/GEJ cancer.
• Evaluation of clinical outcomes following tumor resection (TR) after chemotherapy or anti-PD-1 therapy.
• Immunohistochemical analysis of tumor microenvironment (TME) immune status in resected specimens.

Main Results:

• Tumor resection (TR) after anti-PD-1 therapy significantly improved survival compared to chemotherapy and anti-PD-1 therapy alone.
• Downregulation of human leukocyte antigen (HLA) class I and major histocompatibility complex (MHC) class II observed post-anti-PD-1 therapy.
• Downregulation of HLA class I correlated with increased transforming growth factor-β signaling in the TME.

Conclusions:

• Immune escape via cytotoxic T lymphocytes may occur post-anti-PD-1 therapy due to reduced HLA class I and MHC class II expression.
• Tumor resection (TR) presents a promising strategy for patients with unresectable advanced or recurrent G/GEJ cancer when feasible after anti-PD-1 therapy.