Risk factors and a predictive nomogram for lymph node metastasis in superficial esophageal squamous cell carcinoma

BACKGROUND Superficial esophageal squamous cell carcinoma(ESCC)is defined as cancer infiltrating the mucosa and submucosa,regardless of regional lymph node metastasis(LNM).Endoscopic resection of superficial ESCC is suitable for lesions that have no or low risk of LNM.Patients with a high risk of LNM always need further treatment after endoscopic resection.Therefore,accurately assessing the risk of LNM is critical for additional treatment options.AIM To analyze risk factors for LNM and develop a nomogram to predict LNM risk in superficial ESCC patients.METHODS Clinical and pathological data of superficial ESCC patients undergoing esophagectomy from January 1,2009 to January 31,2016 were collected.Logistic regression analysis was used to predict LNM risk factors,and a nomogram was developed based on risk factors derived from multivariate logistic regression analysis.The receiver operating characteristic(ROC)curve was used to obtain the accuracy of the nomogram model.RESULTSA total of 4660 patients with esophageal cancer underwent esophagectomy.Of these,474 superficial ESCC patientswere enrolled in the final analysis,with 322 patients in the training set and 142 patients in the validation set.Theprevalence of LNM was 3.29%(5/152)for intramucosal cancer and increased to 26.40%(85/322)for submucosalcancer.Multivariate logistic analysis showed that tumor size,invasive depth,tumor differentiation,infiltrativegrowth pattern,tumor budding,and lymphovascular invasion were significantly correlated with LNM.Anomogram using these six variables showed good discrimination with an area under the ROC curve of 0.789(95%CI:0.737-0.841)in the training set and 0.827(95%CI:0.755-0.899)in the validation set.CONCLUSIONWe developed a useful nomogram model to predict LNM risk for superficial ESCC patients which will facilitateadditional decision-making in treating patients who undergo endoscopic resection.