Sadique, G. A. | bioRxiv Science

bioRxiv2025

Tumor Microenvironmental Interactions of Mast Cells and Lymphocytes in Gastric Cancer: A Tissue-Based Study

BackgroundMast cells and tumor-infiltrating lymphocytes (TILs) are key immune components in the tumor microenvironment (TME). Their densities and interaction dynamics may influence gastric cancer progression. This research intends to investigate the density and prevalence of mast cells and CD8+ tumor-infiltrating lymphocytes in gastric adenocarcinoma while evaluating their correlation with tumor grades. MethodsThis cross-sectional observational study was conducted in the Department of Pathology, Satkhira Medical College, from August 2024 to July 2025. Ethical clearance was obtained from the Ethical Review Committee of Satkhira Medical College prior to study initiation. A total of 50 cases of invasive gastric adenocarcinoma were included. Routine Hematoxylin and Eosin (H&E) staining was performed for grading. Mast cell density was assessed using toluidine blue staining and CD8+ TILs by immunohistochemistry. Associations with tumor grades were evaluated using the Chi-square test. ResultMast cell density significantly increased with higher tumor grades (p<0.05). CD8+ TILs, both intra-and peri-tumoral, also showed a statistically significant synergistic higher distribution across tumor grades (p=0.031 and p=0.012, respectively), with higher TIL infiltration in higher grades. ConclusionMast cells and CD8+ lymphocytes are similarly distributed across gastric cancer grades, suggesting their synergistic roles in tumor progression. These findings highlight potential immunoregulatory cross-talk within the TME that may influence therapeutic targeting.

cancer biology↗

bioRxiv2025

EVALUATION OF PECAM-1 EXPRESSION AND MICROVESSEL DENSITY IN GASTRIC ADENOCARCINOMA: A CROSS-SECTIONAL STUDY

BackgroundGastric adenocarcinoma is the fifth most prevalent malignancy globally and ranks sixth in Bangladesh, representing a significant oncological and public health challenge. Gaining in depth knowledge about the tumor microenvironment, particularly the mechanisms of tumor-induced angiogenesis, is essential for the development of more precise and effective targeted therapies. Microvessel density (MVD) serves as a widely recognized measure of angiogenic activity and can be reliably assessed using immunohistochemical staining for PECAM-1 (CD31), a highly specific marker of vascular endothelial cells. MethodsThis cross-sectional observational study was conducted in the Department of Pathology, Satkhira Medical College, from April 2024 to March 2025. A total of 50 cases of invasive gastric adenocarcinoma were included. Routine Hematoxylin and Eosin (H&E) staining was performed for Lauren classification. Immunohistochemistry for PECAM-1 was conducted to highlight microvessels. ResultAmong 50 cases, intestinal-type adenocarcinoma was more frequent than diffuse type. High MVD was observed in 58.1% of intestinal-type cases and 36.8% of diffuse-type cases. The difference in MVD between intestinal and diffuse types was statistically significant (p < 0.05), suggesting higher angiogenic activity in intestinal-type tumors. ConclusionThis study demonstrates that PECAM-1 positive MVD is significantly higher in the intestinal subtype of gastric adenocarcinoma compared to the diffuse subtype. These findings indicate a more angiogenically active tumor microenvironment in intestinal-type tumors, potentially correlating with greater invasive potential and metastatic behavior. PECAM-1 immunostaining provides a valuable tool for quantifying tumor angiogenesis and may serve as a prognostic marker or a basis for anti-angiogenic therapeutic targeting in gastric cancer management.

pathology↗