Log odds of positive lymph nodes show better predictive performance on the prognosis of early-onset colorectal cancer.

backgroundAs the incidence of colorectal cancer tends to be younger, early-onset colorectal cancer (EOCRC) has attracted more attention in recent years. We aimed to assess the optimal lymph node staging system among EOCRC patients, and then, establish informative assessment models for prognosis prediction.

methodsData of EOCRC were retrieved from the Surveillance, Epidemiology, and End Results database. Survival prediction ability of three lymph node staging systems including N stage of the tumor node metastasis (TNM) staging system, lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) was assessed and compared using Akaike information criterion (AIC), Harrell's concordance index (C-index), and likelihood ratio (LR) test. Univariate and multivariate Cox regression analyses were conducted to identify the prognostic predictors for overall survival (OS) and cancer-specific survival (CSS). Effectiveness of the model was demonstrated by receiver operative curve and decision curve analysis.

resultsA total of 17,535 cases were finally included in this study. All three lymph node staging systems showed significant performance in survival prediction (p < 0.001). Comparatively, LODDS presented a better ability of prognosis prediction with lower AIC (OS: 70,510.99; CSS: 60,925.34), higher C-index (OS: 0.6617; CSS: 0.6799), and higher LR test score (OS: 998.65; CSS: 1103.09). Based on independent factors identified from Cox regression analysis, OS and CSS nomograms for EOCRC were established and validated.

conclusionsLODDS shows better predictive performance than N stage or LNR among patients with EOCRC. Novel validated nomograms based on LODDS could effectively provide more prognostic information than the TNM staging system.