Utility of risk prediction nomogram for lymph node metastasis in the elderly with undifferentiated early gastric cancer

Gastric cancer (also called stomach cancer) is the 5th most common cancer the human population suffer from, particularly in East Asia. For effective prevention, it is important to find biomarkers for early-stage diagnosis and prognosis. Further, finding the risk factors that are associated with undifferentiated early gastric cancer is the utmost required. Here, we explored the clinicopathological characteristics of undifferentiated early gastric cancer (EGC) in the elderly, and the risk factors for lymph node metastasis. A total of 187 elderly patients with undifferentiated EGC were selected as subjects, whose clinical data were analyzed retrospectively. They were divided into lymph node metastasis and non-lymph node metastasis groups, and the risk factors for lymph node metastasis were analyzed by univariate and multivariate logistic regression analyses. A nomogram model was established to predict the risk of lymph node metastasis, and then validated. Lymph node metastasis was detected in 32 (17.11%) of the 187 cases. Univariate analysis showed that tumor diameter, depth of invasion, vascular tumor thrombus and local ulcer affected lymph node metastasis (P <0.05). Multivariate logistic regression analysis revealed that tumor diameter >2 cm, invasion to submucosa, vascular tumor thrombus and local ulcer were independent risk factors (P <0.05). The nomogram model was constructed based on the independent risk factors, and its concordance index and area under the receiver operating characteristic curve were 0.756 (95%CI: 0.684-0.830) and 0.758 (95%CI: 0.701-0.815), respectively. Calibration curve and model calibration curve suggested that the predicted probability of the model was consistent with the actual one, indicating high accuracy. Lymph node metastasis of the elderly with undifferentiated EGC is affected by many factors, among which tumor diameter >2 cm, invasion to submucosa, vascular tumor thrombus and local ulcer are independent risk factors.