Effect of preoperative neutrophil-lymphocyte ratio on the surgical outcomes of stage II colon cancer patients who do not receive adjuvant chemotherapy

Background and aims: Selection of appropriate stage II colon cancer patients for adjuvant chemotherapy is critical for improving survival outcome. With the aim of identifying more high risk factors for stage II colon cancer, this study aimed to determine whether the neutrophil-lymphocyte ratio (NLR) is a predictor of surgical outcomes in patients with stage II colon cancer who do not receive adjuvant chemotherapy. Materials and methods: We enrolled 1,040 stage II colon cancer patients who had undergone colectomy at a single institution between January 1995 and December 2005 and did not receive adjuvant chemotherapy. Results: Of these 1,040 patients, 785 (75.5%) patients had a normal NLR and 255 (24.5%) had an elevated NLR. Those with an elevated NLR included patients ≥65 years, T4b cancer, carcinoembryonic antigen ≥5 ng/mL, and tumor obstruction or perforation. Patients with an elevated NLR had a significantly worse overall survival (OS) and worse disease-free survival (DFS) than did patients with a normal NLR. Cox regression analysis revealed that elevated NLR was an independent predictor of OS (P=0.012) but not DFS (P=0.255). Conclusion: An elevated NLR is an independent predictor of OS but not DFS in stage II colon cancer patients who did not receive adjuvant chemotherapy. Preoperative NLR measurement in stage II colon cancer patients may be a simple method for identifying patients with a poor prognosis who can be enrolled in further trials of adjuvant chemotherapy.