Tumor Characteristics and Survival Predictors in Patients With Colorectal Cancer: A Lebanese Single-Center Experience.

Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality worldwide, with incidence rates in Lebanon among the highest in the Middle East and North Africa (MENA) region. Despite this, data on CRC epidemiology, tumor characteristics, and treatment outcomes in MENA populations remain limited. This study aimed to investigate these factors, with the goal of supporting early detection, guiding clinical decision-making, and informing personalized treatment strategies. This retrospective cross-sectional study included patients diagnosed with CRC between 2019 and 2023 at the American University of Beirut Medical Center. Clinical data were retrieved from electronic health records and histopathological reports. Overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) were assessed using Kaplan-Meier survival analysis and multivariable Cox regression models. A total of 349 patients (mean age 61 years) were included. Most tumors were low-grade adenocarcinomas (88.1%; n=306/347), and 73.3% (n=243/331) of patients presented with advanced-stage disease (Stages III/IV). Among patients with available MMR testing (n=181/349), 5.5% (n=10/181) were mismatch repair-deficient (dMMR) by immunohistochemistry. Molecular testing revealed KRAS mutations in 42.9% (n=70/163 tested) and BRAF mutations in 7.0% (n=9/128 tested). Smoking (HR = 2.58, p = 0.007) and age ≥65 years (HR = 1.98, p = 0.050) were associated with reduced OS. Patients with inflammatory bowel disease had a significantly increased risk of progression (HR = 9.39, p = 0.032). Left-sided tumors were associated with improved OS (HR = 0.42, p = 0.018). This study identifies key risk factors, including tumor location, age, IBD, and smoking, influencing survival outcomes in Lebanese patients with CRC. Findings support implementation of risk-adapted screening strategies and population-specific therapeutic approaches in Middle Eastern settings.