Multivariate survival analysis of patients with stage III–IV colon cancer: clinical and biological factors and the impact of treatment regimen
Purpose of the study . To evaluate treatment outcomes in patients with stage III–IV colon cancer residing in the Southern Federal District of the Russian Federation. Patients and method s. A retrospective analysis was performed of the medical records of 200 patients with stage III–IV colon cancer who underwent treatment and follow-up at the National Medical Research Centre for Oncology between 2019 and 2024. Overall survival (OS) was assessed, as well as its association with sex, disease stage, primary tumor location, KRAS, NRAS, and BRAF mutation status, tumor microsatellite instability (MSI) status, and antitumor treatment strategy. Results . The median follow-up from the time of presentation to the National Medical Research Centre for Oncology was 1.4 years. The 5‑year OS rate was 31 %, with a median overall survival of 3.4 years. The 5‑year OS rate was significantly associated with disease stage, reaching 46 % in patients with stage III disease and 18 % in those with stage IV disease (p = 0.00005). The presence of KRAS mutations (3‑year OS: 53 % in the wild-type group vs. 28 % in the mutant group), BRAF mutations (42.5 % vs. 18 %, respectively), and MSI status (67 % for MSI tumors vs. 42.5 % for microsatellite-stable [MSS] tumors) significantly influenced survival outcomes. Among patients with stage IV disease, survival was also associated with the type of targeted therapy administered. Improved survival was observed in patients receiving combined inhibition of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) compared with VEGF inhibitor-based therapy alone. The 3‑year OS rate was 66 % (median OS, 4.1 years) in the combined EGFR/VEGF inhibition group versus 31 % (median OS, 2.1 years) in the VEGF inhibitor group. Conclusion . Nearly half of all colon cancer cases (47.6 %) were diagnosed at advanced stages, which are associated with an unfavorable prognosis, particularly in tumors harboring pathogenic mutations and exhibiting a microsatellite-stable phenotype. These findings underscore the importance of genetically and epigenetically guided therapeutic approaches aimed at identifying novel therapeutic targets and developing more effective treatment strategies.