Predictive value of CK7/CK20 expression patterns for gastric cancer differentiation: an integrated gastroscopy-pathology analysis

The expression of cytokeratin CK7 and CK20 in gastric cancer exhibits heterogeneity, potentially correlating with tumor differentiation. This study aimed to investigate the predictive value of CK7/CK20 immunohistochemical expression patterns in gastroscopically obtained biopsy specimens for gastric cancer differentiation. Methods: This retrospective diagnostic study enrolled 229 patients with surgically confirmed gastric cancer. Gastroscopy biopsy specimens underwent CK7 and CK20 immunohistochemical staining, categorized into four expression patterns. Fisher’s exact test compared intergroup distribution differences, while the Cochran-Armitage trend test analyzed correlations between expression patterns and differentiation grades. Results: The CK7⁻/CK20⁺ pattern was most prevalent in the high differentiation group (54.5%) and decreased significantly with decreasing differentiation ( p < 0.0001). The CK7⁺/CK20⁻ pattern dominated in the low differentiation group (66.1%) and increased significantly with decreasing differentiation ( p < 0.0001) Trend analysis revealed a significant positive correlation between CK7⁺/CK20⁻ expression and low differentiation tumors, while CK7⁻/CK20⁺ expression was significantly associated with high differentiation tumors. Intergroup comparisons demonstrated significant differences in expression pattern distribution between the low differentiation group and both the high and moderate differentiation groups ( p < 0.001). CK7/CK20 dual-marker immunohistochemical typing, particularly the CK7⁺/CK20⁻, is superior to single-marker analysis and can serve as a highly specific preoperative predictor of low differentiation gastric cancer. Conclusion: The CK7/CK20 expression pattern is closely associated with the differentiation grade of gastric cancer. CK7⁺/CK20⁻ may serve as a potential preoperative biomarker for identifying poorly differentiated gastric cancer, helping to provide additional biological information for preoperative risk stratification.