A Conserved Fibroblast-Myeloid Gene Signature in Digestive Cancers: Multi-Omics Integration Identifies <i>DCN</i>, <i>COL10A1</i>, <i>CTHRC1</i>, and <i>TREM2</i> as Candidate Microenvironmental Markers

Digestive cancers exhibit high heterogeneity and poor prognosis, yet whether their tumor microenvironments share conserved stromal-immune interactions remains unclear. Here, we performed an integrative multi-omics analysis across seven digestive cancer types and identified a conserved four-gene signature-<i>DCN</i>, <i>COL10A1</i>, <i>CTHRC1</i>, and <i>TREM2</i>-that is consistently enriched in matrix cancer-associated fibroblasts (mCAFs) and myeloid cells. Single-cell RNA sequencing revealed that <i>DCN</i>, <i>COL10A1</i>, and <i>CTHRC1</i> are predominantly expressed in mCAFs, while <i>TREM2</i> is enriched in myeloid cells and, to a lesser extent, in antigen-presenting CAFs(apCAFs). Cell-cell communication analysis consistently identified a fibroblast-to-myeloid signaling network centered on ECM-CD44 interactions across all examined cancer types, providing a candidate framework for intercellular crosstalk. Multi-omics profiling further characterized the genomic, epigenetic, and immune correlates of this signature. Collectively, these findings identify a conserved stromal-myeloid gene signature across digestive cancers and provide a candidate gene set for future diagnostic and therapeutic exploration.