Abstract
This bicenter study evaluates the prognostic value of No.253 lymph node metastasis and establishes a dynamic prediction model for stage III rectal cancer. Retrospective analysis included 956 pTNM III stage rectal cancer patients undergoing radical resection (2016-2024) at two tertiary centers. Propensity score matching (PSM, 1:4 ratio) balanced baseline characteristics between No.253-positive (n = 78) and negative (n = 260) cohorts. Before PSM, the No.253 metastasis rate for stage III rectal cancer was 8.3%, multivariate Cox regression analysis showed that No.253 lymph node metastasis was an independent risk factor for OS (HR = 2.780, 95% CI: 1.874-4.124, P < 0.001). Furthermore, after PSM, the median follow-up period was 32.0 months (range: 1.0 to 92.0 months). The 3-year overall survival rate was 60.6% in the positive group and 81.7% in the negative group (P < 0.001). Multivariate Cox regression identified No.253 involvement as an independent OS determinant (HR = 3.171, 95% CI 2.016-4.986, P < 0.0011), alongside sex, circumferential resection margin (CRM) positivity and advanced pTNM stage. The developed dynamic nomograms, directly accessible at URL: https://pcrpredict.shinyapps.io/No253/ , showed strong predictive accuracy (1-/3-/5-year C-indices: 0.741/0.719/0.738), maintained across external validation cohorts (Zhangzhou: 0.816/0.649/0.619; Union: 0.726/0.674/0.647). Decision curve analysis confirmed clinical utility. No.253 Lymph node status has a significant impact on long-term prognosis after surgery for stage III rectal cancer. The validated web-based model enables personalized prognosis prediction.