Background: Tissue factor (TF) is a transmembrane protein that plays a crucial role in thrombosis. TF expression is elevated in various types of cancer, including colorectal cancer (CRC) and is associated with more aggressive disease and poor prognosis. The aim of this study was to evaluate TF expression in patients (pts) with metastatic CRC (mCRC) enrolled in the CALGB (Alliance)/SWOG 80405 clinical trial. Understanding the relationship between TF expression and mCRC will provide insights into the role of coagulation in the progression and prognosis of this disease and may have therapeutic implications, particularly in the setting of recent approval of a TF antibody drug conjugate for metastatic cervical cancer and other agents in the pipeline. Methods: 433 pts with mCRC treated with bevacizumab (Bev, n = 226) or cetuximab (Cet, n =207) in combination with first-line chemotherapy in CALGB/SWOG 80405 were included in the analysis.TF RNA was isolated from FFPE tumor samples and sequenced on the HiSeq 2500 (Illumina). Overall survival (OS) and progression-free survival (PFS) were compared between groups of pts categorized by tertiles of TF expression: high (H), medium (M) and low (L). Sensitivity analyses were conducted after stratifying by side. Logrank P-values describe differences without adjustment for pt characteristics. Transcriptome-wide gene association analysis was performed using linear regression, adjusting for age, sex, ethnicity, ECOG PS, location, number of metastases, KRAS, MSI status, treatment with FOLFOX or FOLFIRI, and the first 3 principal components from the RNA-seq data. Gene Ontology enrichment analysis was conducted with the top 100 TF-associated genes. Results: TF expression is associated with genes related to maintenance of epithelium, cell adhesion, and migration, immunoregulatory cytokine production, and metabolic, HER2, and MAP/Kinase pathways. TF-L showed significantly longer median (m)PFS (13.4 vs 10.1 vs 9.2 months (mo), p=0.0022) and mOS (35.4 vs 30.9 vs 25.2, p=0.0051) in the entire cohort. In Cet treated pts, TF-L had significantly longer mOS (41.3 vs 29.9 vs 26.1 mo, p=0.0013). In pts treated with FOLFOX, TF-L had significantly longer PFS (13.2 vs 10.9 vs 8.2 mo, p=0.0014) and OS (33.4 vs 30.9 vs 22.4 mo, p=0.0044). Pts with liver metastases and TF-H had worse PFS (9.2 vs 9.9 vs 13.5 mo, p=0.006) and OS (23.6 vs 29.9 vs 35.1 mo, p=0.016). Conclusions: Our results suggest that pts with TF-L tumors with liver metastases have improved prognosis compared to pts with TF-H and may benefit from FOLFOX and Cet-based treatment. Findings provide rationale for further evaluation of TF as a predictive biomarker and potential therapeutic target in CRC. Trial Identifier NCT00265850. Support: P30CA014089, U10CA180821, U10CA180882, U10CA180820 and UG1CA233277; UG1CA180830, U10CA180888; Pfizer, Genentech. https://acknowledgments.alliancefound.org.