Establishment and Validation of Prediction Models for Lymph Node Metastasis and Long-Term Survival in Patients with T1b Early Gastric Cancer: A Retrospective Cohort Study with 10-Year Follow-Up.

[BACKGROUND] T1b gastric cancer, characterized by tumor invasion into the submucosa, presents a therapeutic dilemma regarding the need for adjuvant therapy owing to varying rates of lymph node metastasis (LNM). This study aimed to develop and validate comprehensive nomogram models for predicting LNM risk and long-term survival outcomes in patients with T1b gastric cancer.

[PATIENTS AND METHODS] A retrospective cohort study was conducted on 362 patients with pathologically confirmed T1b gastric cancer who underwent radical gastrectomy with D2 lymph node dissection at a single institution between 2014 and 2024. Patients were stratified into LN (lymph node-positive) and LN (lymph node-negative) groups. Multivariate logistic regression identified independent risk factors for LNM, while Cox proportional hazards models assessed prognostic factors for overall survival (OS) and recurrence-free survival (RFS). Nomogram models were constructed and internally validated using bootstrap resampling.

[RESULTS] Among 362 patients, 92 (25.4%) had LNM. Independent predictors of LNM included tumor size ≥ 3 cm (odds ratio [OR] 2.84, 95% confidence interval [CI]: 1.62-4.98, p < 0.001), lymphovascular invasion (OR 4.21, 95% CI: 2.45-7.23, p < 0.001), poor differentiation (OR 3.12, 95% CI: 1.78-5.47, p < 0.001), and perineural invasion (OR 2.56, 95% CI: 1.23-5.32, p = 0.012). The LNM prediction nomogram showed excellent discrimination (area under the curve [AUC] 0.843, 95% CI: 0.801-0.885) and calibration. The integrated survival nomogram incorporating LNM risk demonstrated superior predictive performance for 5-year OS (C-index 0.782) compared with traditional staging (C-index 0.681). Decision curve analysis confirmed clinical utility across relevant threshold probabilities.

[CONCLUSIONS] Our validated nomogram models provide accurate individualized predictions for LNM risk and long-term survival in patients with T1b gastric cancer, potentially guiding personalized treatment decisions regarding adjuvant therapy and extent of lymphadenectomy.