Primary Tumor Lymph Node Status Affects Overall and Recurrence-free Survival after Curative Resection of Colorectal Liver Metastases

Abstract

Purpose: The primary cause of mortality in colorectal cancer is metastatic disease. This study investigated the effect of lymph node status of the primary tumor, on long-term outcomes of patients undergoing curative resection for colorectal liver metastases (CRLM). Methods: Patients in our institutional tissue bank, who underwent curative resection for CRLM, were included in this retrospective study. Patients were split into two groups according to the lymph node status from resection of the primary tumor, either N0/N1 or N2. Overall survival (OS) and recurrence-free survival (RFS) were analyzed, and risk factors were identified using Cox regression analysis. Results: After excluding resections of recurrent metastases, 181 patients were included, of which 123 (68%) and 58 (32%) were in the N0/N1 and N2 groups, respectively. The N2 group showed a more advanced T-stage (p = 0.001), a higher incidence of distant metastases (p = 0.048), more frequent non-R0 resection of the primary tumor (p = 0.047) and younger age (p = 0.003). There were no other significant differences in population characteristics or treatment strategies. Significantly reduced OS (p=0.024) and RFS (p = 0.004) were observed in the N2 group, which was confirmed in the multivariate analysis for both OS (p = 0.017; HR 11.935: 95% CI 1.560 – 91.306) and RFS (p < 0.002; HR 4.058; 95% CI 1.637 – 10.060). Conclusion: Patients with advanced lymphatic metastasis of the primary tumor have reduced overall and recurrence-free survival after curative resection of CRLM. Closer follow-ups and a more aggressive postoperative systemic treatment strategy may be of benefit to these patients.