S611 Prognostic Role of D-Dimer in Predicting Survival Outcomes in Metastatic Colorectal Cancer: A Meta-Analysis

Introduction: Despite advances in diagnosis and treatment, colorectal cancer remains a significant public health challenge, contributing to high mortality rates worldwide. Among potential biomarkers, D-dimer, a widely used indicator of activated coagulation and fibrinolysis, has been proposed as a valuable prognostic biomarker in operable CRC. However, its prognostic value in metastatic colorectal cancer (mCRC) patients remains understudied. This meta-analysis evaluates the prognostic significance of D-dimer levels, offering insights into overall survival (OS) and progression-free survival (PFS) in mCRC patients. Methods: A comprehensive literature search was conducted using PubMed and Google Scholar, and the snowballing technique was used to identify relevant studies. Eligible studies included those evaluating baseline D-dimer levels in mCRC patients and their impact on OS and/or PFS published between 2004 and 2020. Data extraction focused on study design, sample size, D-dimer cut-off levels, and statistical outcomes. Binary random-effects models were used to estimate pooled hazard ratios (HR) and 95% confidence intervals (CI). Heterogeneity was assessed using I² statistics. Subgroup and sensitivity analyses were conducted to explore potential variations across study designs. Results: A total of 6 studies, encompassing 554 mCRC patients with a median age range of 23-85 years, in which men represented 56% of the cohort, were analyzed. Elevated D-dimer levels were significantly associated with poor OS, with a pooled HR of 1.46 (95% CI: 1.16-1.84, P < 0.01) and moderate heterogeneity (I² = 50.46%). Subgroup analysis demonstrated consistent associations in prospective cohort studies (HR: 1.41, 95% CI: 1.20-1.65, I² = 0%) and retrospective observational studies (HR: 2.83, 95% CI: 1.58-5.07, I² = 0%). In contrast, the association between elevated D-dimer levels and PFS was not statistically significant, with a pooled HR of 1.13 (95% CI: 0.98-1.30, P = 0.10) and no heterogeneity (I² = 0%). Sensitivity analyses confirmed the robustness of the OS findings. Conclusion: Our meta-analysis highlights the prognostic utility of elevated plasma D-dimer levels in mCRC patients, demonstrating their significant association with poor overall survival. The findings underscore the potential of D-dimer as a valuable biomarker in mCRC. However, no statistically significant association was observed with progression-free survival, highlighting the need for further research to clarify its role in predicting disease progression.