Prognostic Implications of Node Status in Colon Adenocarcinoma With Synchronous Liver Metastasis

Introduction: In patients with metastatic colon cancer undergoing curative resection, lymph node status does not change management or staging as per current guidelines. The aim of this project is to assess the prognostic value of lymph node status and yield in clinical stage IV-A colon adenocarcinoma undergoing curative resection. Methods: This is a retrospective cohort study from the National Cancer Database from 2010 to 2018 that examines adults with colon adenocarcinoma with synchronous liver metastasis who underwent primary colectomy, hepatic metastasectomy, and systemic therapy. Survival analysis of subgroups with node-positive and node-negative was performed by Kaplan–Meier analysis and the Cox proportional hazards model. Results: Of 2071 patients with clinical stage IV-A colon adenocarcinoma, 25.6% had negative lymph nodes (N-LNs). Patients with N-LNs had higher median survival compared to patients with positive lymph nodes (62.03 versus 48.69 mo, P < 0.001) and lower mortality risk (hazard ratio 0.75, P < 0.001). Resection of ≥12 lymph nodes was associated with longer median survival compared to patients with <12 lymph nodes in patients with positive lymph nodes (49.64 versus 28.09 mo, P < 0.001) but not in patients with N-LNs (63.01 versus 55.46 mo, P = 0.09). This relationship remained regardless of chemotherapy sequence. Conclusions: In the setting of hepatic metastases in clinical stage IV colon adenocarcinoma, lymph node status is prognostic as N-LNs are associated with increased overall survival. Further research is necessary to delineate underlying differences in tumor biology and to help predict nodal status preoperatively.