Prognostic and Molecular Characterization of Metastatic Transverse Colon Cancer: Insights From a Single-Center Retrospective Study

Introduction: Metastatic transverse colon cancer (TCC) represents a unique subset of colorectal cancer with features of both right and left colon tumors due to its distinct embryologic origin. This study retrospectively analyzes the clinical, pathological, and molecular factors influencing survival outcomes in TCC patients treated at a single center.

Methods: For this study, we reviewed the files of 372 metastatic patients and analyzed the data of 71 patients with a diagnosis of TCC in detail. The remaining patients were patients with right or left colon tumors and we compared the overall survival (OS), molecular mutations (KRAS, NRAS, BRAF, MSI status), and clinicopathological features of our patients with transverse colon tumors with these patients.

Results: The median OS for TCC patients was 19.7 months, with metastasectomy and Eastern Cooperative Oncology Group (ECOG) performance status emerging as significant prognostic factors. Molecular analyses revealed KRAS mutations in 49% and BRAF mutations in 13% of TCC cases, aligning TCC closer to right-sided tumors in certain molecular characteristics. However, histopathologic diversity, including mucinous histology in 20% of TCC cases, indicated a need to consider TCC as a distinct entity.

Conclusion: These findings underscore the complex biological nature of TCC and the necessity for tailored therapeutic approaches, especially as survival rates remain suboptimal. Further multicenter, prospective studies are recommended to establish refined treatment strategies for TCC patients.