241. A VALIDATED NOMOGRAM PREDICTING LYMPH NODE METASTASIS OF T2N0 ESOPHAGEAL SQUAMOUS CELL CARCINOMA FOR CLINICAL DECISION-MAKING

Abstract

Abstract Clinical T2N0 esophageal cancer is the treatment threshold for neoadjuvant therapy. Because of limitations in the diagnostic accuracy of endoscopic ultrasound and positron emission tomography-computed tomography, a number of these patients were verified to have lymph node involvement after esophagectomy. We aimed to develop and validate a nomogram for predicting nodal disease and selecting patients eligible for neoadjuvant therapy. A predictive nomogram was constructed using the training cohort. We identified patients who underwent esophagectomy for pT2 esophageal squamous cell carcinoma in our department from January 2009 to December 2014. Binary logistic regression was used to determine risk factors for lymph node metastasis. We selected predictors considering both statistical significance and clinical importance. Furthermore, bootstrapping was used to assess the predictive accuracy. An independent cohort from the same institution was used to validate this model. This cohort included consecutive patients with cT2N0 who underwent esophagectomy between January 2015 and April 2019. The training cohort comprised 551 patients. Logistic regression identified six variables that were associated with lymph node metastasis, including tumor diameter (OR: 2.43, 95% CI: 1.44–4.09; P = 0.001), tumor length (OR: 10.63, 95% CI: 6.32–17.89; P < 0.001), circumferential involvement (OR: 5.14, 95% CI: 6.3–17.9; P < 0.001), differentiation (OR 3.65, 2.24–5.93; P < 0.001), lymphovascular invasion (OR 12.18, 95% CI: 5.91–25.21; P < 0.001), and the presence of multifocal tumors (OR: 8.67, 95% CI: 1.47–51.14; P = 0.017). The C-index was 0.914 (95% CI: 0.889–0.938) in the training cohort and 0.962 (95% CI: 0.939–0.985) in the validation cohort. A validated nomogram for patients with clinical T2N0 esophageal squamous cell carcinoma may aid in assessing the risk of lymph node metastasis. Neoadjuvant therapy is recommended for high-risk patients.