The role and prognostic impact of lymph node ratio on stage III colorectal cancer

AIM: The aim of this study was to evaluate the prognostic significance of the lymph node ratio (LNR) in patients with stage III colorectal cancer. MATERIALS AND METHODS: We included 35 stage III colorectal cancer patients who underwent a curative resection at the County Clinic Hospital, Cluj-Napoca, 5(th) Surgical Clinic between January 2006-July2008. Patients were categorized into LNR groups 1 to 5 according to cut-off points: <0.1; 0.21; 0.36; 0.6; >0.61. The Kaplan-Meier and the Cox proportional hazard models were used to evaluate the prognostic effect according to the LNR. RESULTS: From one hundred forty-eight patients who underwent colorectal cancer resection, 33.1 % were stage III and 35 patients met the study inclusion criteria. The five-year survival rate in N1 group was 64.62% compared to the N2 group, where it was 8.57% (p<0.001) The lymph node ratio (LNR) groups consisted of 5 cases (14.2%) in LNR1 group (<0.1), five-year survival rate 100%, 6 cases (17.14%) in LNR2 group (0.11–0.21), five-year survival rate 83.33%, 8 cases (22.8%) in LNR3 group (0.22–0.36), five-year survival rate 37.5%, 12 cases (34.28%) in LNR4 group (0.37–0.60), survival rate 0%, and LNR5 group (>0.6). The relationship between the five-year survival rates in the five LNR groups results in a statistically significant proportionality (p<0.001). CONCLUSION: Lymph node ratio can be considered a more accurate and potent modality for prognosis in stage III colorectal cancer and may improve stratification in this heterogenous group of patients.