Log odds of positive nodes (LODDS), defined as the log of the ratio between the number of positive nodes and the number of negative nodes, has been recently introduced as a tool in predicting prognosis. This study aims to establish the effective and prognostic value of LODDS in predicting the survival outcome of CRC patients undergoing surgical resection. The study population is represented by 323 consecutive patients with primary colon or rectal adenocarcinoma thatunderwent curative resection. LODDS values were calculated by empirical logistic formula, log(pnod + 0.5)/(tnod - pnod + 0.5). It was defined as the log of the ratio between the number of positive nodes and the number of negative nodes. The patients were divided into three groups: LODDS0 (≤ - 1.36), LODDS1 (> - 1.36 ≤ - 0.53) and LODDS2 (> - 0.53). Kaplan-Meier curve analyses showed 3-year OS rates of the patients staged by LODDS classification. These values were 88.3, 74.8 and 61.8% for LODDS0, LODDS1 and LODDS2, respectively (P ≤ 0.001). In a multivariate analysis, LODDS is an independent prognostic factor of 3-year OS. This is in contrast to pN stage and lymph node ratio, which shows no statistical significance. ROC analyses showed that LODDS predicted OS better than lymph node ratio. LODDS classification has a better prognostic effect than pN stage and lymph node ratio. LODDS offers a finer stratification and accurately predicts survival of CRC patients.
Keywords: Adenocarcinoma; Colon cancer; LODDS; Lymph nodes; Rectum cancer.