The Prognostic Value and Immunological Role of CD44 in Pan-Cancer Study

Abstract Background To investigate the correlation between cluster of differentiation-44 (CD44) expression and immunotherapy response and identify its possible predictive value in pan-cancer. Methods Datasets of 33 cancer types from The Cancer Genome Atlas (TCGA) database were applied to investigate the relationship of CD44 expression with prognosis, tumor mutational burden (TMB), and microsatellite instability (MSI), and determine its potential prognostic value in pan-cancer. Patients were split into high-risk and low-risk cancer groups based on the survival outcomes of various cancer types. Additionally, the underlying mechanisms of CD44 in the tumor microenvironment (TME) were analyzed using ESTIMATE and CIBERSORT algorithms and Gene Set Enrichment Analysis (GSEA). Results Variable expression levels of CD44 between tumor and adjacent normal tissues were identified in pan-cancer datasets, and the survival analysis revealed that CD44 expression was associated with multiple clinical annotations and survival indicators in several cancers. Besides, the expression of CD44 was significantly associated with TMB and MSI in some types of cancer. Conclusion Our study demonstrated that CD44 shows great promise as a prognostic biomarker in numerous cancers, which will assist in developing new strategies in immunotherapy.