Objective:

To compare CD4+ T cell, CD8+ T cell infiltration and PD-L1 expression between paired biopsy and resection specimens in gastric and colorectal adenocarcinoma, and evaluate their clinical significance.

Approach:

Key Findings:

• In gastric adenocarcinoma, resection specimens showed significantly higher CD4+ T cell, CD8+ T cell density and PD-L1 expression than biopsies (all P<0.05), with CD4+ T cells positively correlated with CA19-9 (R=0.523, P=0.026).
• In colorectal adenocarcinoma, only CD8+ T cell density was higher in resection specimens (P=0.0446).
• CD4+ T cells negatively correlated with Ki-67 in colorectal adenocarcinoma (R=-0.370, P=0.019).
• CD4+/CD8+ ratio negatively correlated with mismatch repair protein expression in colorectal adenocarcinoma (R=-0.342, P=0.029).
• Preoperative neutrophil-to-lymphocyte ratio positively correlated with tumor diameter in both cancers.

Interpretation:

Biopsy specimens inadequately represent the immune microenvironment of resection specimens, especially in gastric adenocarcinoma.

Limitations:

• ROC analysis demonstrated limited predictive value of biopsy specimens for surgical findings, particularly in colorectal cancer (AUC 0.5-0.7).

Conclusion:

Tumor-type-specific immune assessment of biopsies is essential for guiding precise immunotherapy decisions.

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This content is an AI-generated, fully rewritten summary based on a published scholarly article. It does not reproduce the original text and is not a substitute for the original publication. Readers are encouraged to consult the source for full context, data, and methodology.