The association between the lymph node ratio, surgical margin, and survival in patients with colon cancer receiving adjuvant chemotherapy

OBJECTIVES: To investigate the prognostic significant of lymph node ratio and surgical margins in patients with colon cancer undergoing surgery. METHODS: This observational and retrospective study was conducted at Karadeniz Technical University Medical Faculty, between 1 January, 2010 and 31 November, 2020. A series of 137 patients who had undergone surgical resection of colon carcinoma were included in this study. mLNR, defined as the ratio of the number of mLNs to the number of examined lymph nodes, was calculated in colorectal cancer cases with lymph node metastasis. Patients were divided into three groups; LNR1 (< 0.25), LNR2 (0.25-0.6) and LNR3 (> 0.6). RESULTS: Mean disease-free survival was 79.2 months (95% CI 71.0-87.4). The mean expected survival time was 73.5 months (95% CI: 65.9-81.0). As the metastatic LN ratio increased, the rate of local recurrence or distant metastasis increased statistically significantly (p=0.007). As the metastatic LN ratio increased, the death rate increased statistically significantly (p=0.036). Metastatic lymph node ratio did not have a statistically significant effect on overall survival in patients with stage-3 and more than 12 LNs removed (p=0.069). There was no statistically significant association between the closeness of the surgical margin and disease-free survival in stage 1 (p=0.505) and stage-2 (p=0.161). There was no statistically significant association between the closeness of the surgical margin and overall survival among patients with stage 1 (p=0.494) and stage 2 (p=0.265). CONCLUSION: A high metastatic LNR is associated with poorer overall and disease-free survival.