Clinicopathological Factors and Nomogram Construction for Lymph Node Metastasis in Locally Advanced Gastric Cancer.

Background: The research on lymph node metastasis (LNM) in locally advanced gastric cancer (LAGC) infiltrating the subserous tissue and serous membrane (T3-4a) is significantly inadequate. This study aims to explore the clinicopathological factors related to LNM in stages T3 and T4a LAGC, while also developing predictive nomograms.

Methods: After systematic searching and rigorous screening, 1995 T3 and 1244 T4a LAGC cases who underwent surgery without neoadjuvant or perioperative chemotherapy were selected. The risk factors associated with LNM were identified using both univariate and multivariate logistic regression analyses. Subsequently, the independent variables identified through the multivariate analyses were utilized to construct a nomogram.

Results: The incidence of LNM in T3 and T4a LAGC was 77.1% (1539/1995) and 83.8% (1043/1244), respectively. The following factors were found to be independently associated with LNM in T3 LAGC: preoperative serum albumin <41g/L (P=0.007), gastrointestinal obstruction (P<0.001), tumor location (P=0.040), tumor size >4cm (P=0.002), mixed (P=0.001) and undifferentiated histological types (P=0.002), presence of lymphovascular invasion (LVI) (P<0.001) and nerve invasion (P<0.001). Additionally, in T4a LAGC cases, serum albumin < 39g/L (P=0.004), tumor size >6cm (P=0.020), mixed (P<0.001) and undifferentiated histological types (P<0.001), presence of gastrointestinal hemorrhage (P=0.016), neuroendocrine differentiation (P=0.024), and LVI (P<0.001) independently influenced the occurrence of LNM.

Conclusion: This study identified the risk factors associated with LNM in T3-4a LAGC cases and constructed nomograms, thereby providing valuable guidance for formulating and implementing a multidisciplinary perioperative treatment program.