Background. Metastases at regional lymph nodes could easily occur in patients with high-histological-grade colorectal cancer (CRC). However, few models were built on the basis of lymph nodes to predict the outcome of patients with histological grades III-IV CRC. Methods. Data in the Surveillance, Epidemiology, and End Results databases were used. Univariate and multivariate analyses were performed. A personalized prediction model was built in accordance with the results of the analyses. A nomogram was tested in two datasets and assessed using a calibration curve, a consistency index (C-index), and an area under the curve (AUC). Results. A total of 14,039 cases were obtained from the database. They were separated into two groups (9828 cases for constructing the model and 4211 cases for validation). Logistic and Cox regression analyses were then conducted. Factors such as log odds of positive lymph nodes (LODDS) were utilized. Then, a personalized prediction model was established. The C-index in the construction and validation groups was 0.770. The 1-, 3-, and 5-year AUCs were 0793, 0.828, and 0.830 in the construction group, respectively, and 0.796, 0.833, and 0.832 in the validation group, respectively. The calibration curves showed well consistency in the 1-, 3- and 5-year OS between prediction and reality in both groups. Conclusion. The nomogram built based on LODDS exhibited considerable reliability and accuracy.

Introduction: Lymphovascular invasion (LVI) is a micropathological tumor factor believed to increase the risk of tumor metastasis and spread. Propensity score matching (PSM) is a statistical method that can control confounding factors. Current research rarely considers the confounding relationship between LVI and other factors that may influence prognosis. This study aimed to investigate the relationship between LVI and prognosis in patients with stage I–III colorectal cancer (CRC) by using propensity score matching (PSM). Methods: This was a retrospective study involving 610 patients. PSM was used to adjust for baseline differences between the groups. The survival rates were calculated. A nomogram was constructed based on the Cox proportional hazards model before matching. The C-index, receiver operating characteristic curve (ROC), and calibration curve were used to evaluate the nomogram. Results: A total of 150 patients tested positive for LVI, accounting for 24.6% of the total, and 120 couples of patients were identified after PSM. The survival curve and Cox proportional hazards model after matching confirmed the adverse effects of LVI on tumor prognosis. The Cox proportional hazards model before matching showed that age, carcinoembryonic antigen level, T stage, N stage, histologic grade and LVI were independent prognostic factors. The C-index of the nomogram established based on the Cox proportional hazards model was 0.787 (95% CI=0.728–0.845). The areas under the curve were 0.796 in the 3-year ROC. Conclusions: LVI is an adverse prognostic factor in patients with stage I-III colorectal cancer.