Objective To construct and validate a nomogram model for predicting the risk of complications with Clavien-Dindo grade ≥ Ⅱ within 30 days after radical gastrectomy in young and middle-aged patients with gastric cancer.

Methods The clinical data of young and middle-aged patients treated with radical gastrectomy for gastric cancer at Lu'an People's Hospital from 2019 to 2021 were retrospectively collected. Taking complications with Clavien-Dindo grade ≥ Ⅱ within 30 days after surgery as the outcome indicator, the independent risk factors were screened through univariate and multivariate logistic regression analyses, and a nomogram prediction model was constructed using R software based on the regression results. The discriminative efficacy of the model was evaluated by the consistency index (C-index) and area under the ROC curve (AUC), the calibration curve was used to assess its predictive consistency, and the decision curve analysis (DCA) was employed to quantify its clinical application value.

Results A total of 106 young and middle-aged patients treated with radical gastrectomy for gastric cancer were included. Among them, 27 cases developed complications of Clavien-Dindo grade ≥ Ⅱ within 30 days after the operation. The results of multivariate logistic regression analysis showed that the diabetes (OR = 12.308, 95%CI: 2.510–60.368, P = 0.002), prognostic nutritional index (PNI) ＜ 49.6 (OR = 5.556, 95%CI: 1.882–16.402, P = 0.002), tumor diameter ＞ 4 cm (OR = 2.977, 95%CI: 1.020–8.690, P = 0.046) and preoperative CEA level ＞ 5 ng/mL (OR = 3.917, 95%CI: 1.041–14.739, P = 0.043) were the independent risk factors for postoperative complications of grade ≥ Ⅱ. Based on the above variables, a nomogram risk prediction model was constructed and internally validated using the Bootstrap method (repeated sampling 1000 times). The consistency index (C-index) of the model was 0.818 (95%CI: 0.740–0.897), and the area under the ROC curve (AUC) was 0.818 (95%CI: 0.739–0.898), which indicated that the model had good discriminatory ability. The calibration curve showed that the predicted probability was highly consistent with actual observed probability. Decision curve analysis further confirmed that this model had high net benefits and application value in clinical practice.

Conclusions Diabetes, PNI ＜ 49.6, tumor diameter ＞ 4 cm and preoperative CEA level ＞ 5 ng/mL are identified as the independent risk factors for Clavien-Dindo≥ grade Ⅱ complications in young and middle-aged patients with gastric cancer after surgery. The nomogram model constructed by integrating the above indicators can visually assess the risk of postoperative complications for individuals. It has certain prospects for clinical application.