The prognostic impact of the log odds of positive lymph nodes in colon cancer

Aim This study aimed to investigate the prognostic impact of the log odds of positive lymph nodes (LODDS) in colon cancer. Method Four hundred and forty patients with colon cancer were divided into three each groups according to their lymph node ratio (LNR) and LODDS. Survival analysis was performed. Results The 5-year overall survival (OS) rate was 70.2%. In univariate analysis age, pT and pN stage, tumour grade, lymphatic, venous and perineural invasion, surgical margin clearance, LNR and LODDS were significantly associated with OS. In multivariate analysis age, surgical margins, perineural invasion and LODDS were found to be independent prognostic factors. In subgroup analysis of patients with an inadequate number of examined lymph nodes (NELN) (n = 76) and node-negative patients (n = 210), LODDS retained its prognostic value, whereas the impact of LNR was not statistically significant (P = 0.063). The overall survival rates of node-negative patients in the LODDS groups 0, 1 and 2 were 81%, 74.2% and 50%, respectively (P = 0.020). LNR and LODDS classifications were both significantly associated with survival in Stage III colon cancer, but only LODDS was an independent prognostic factor. Conclusion Conventional TNM staging for nodes (pN) and LNR status cannot reliably classify node-negative patients into homogeneous groups. LODDS provides more valuable information than LNR independently of the NELN.