Preoperative EUS evaluation of the response to neoadjuvant therapy for gastric and esophagogastric junction cancer is correlated with survival: A single retrospective study of 97 patients

BACKGROUND AND OBJECTIVES: The European Society for Medical Oncology suggests performing EUS staging for esophagogastric junction and gastric cancers to further assess the T and N stages. The use of EUS after neoadjuvant therapy (NT) is still under debate. We aimed to evaluate the contribution of EUS after NT to staging, therapeutic choices, and prognosis prediction. SUBJECTS AND METHODS: In 97 patients with esophagogastric junction and gastric cancers who received NT (chemotherapy or radiochemotherapy) followed by carcinologic surgery, EUS was performed before (uT, uN) and after (yuT, yuN) NT. We compared the results of EUS staging after NT (yuT and yuN) and final histology (ypT and ypN). We analyzed the correlation between overall survival (OS), disease-free survival (DFS), and the objective and subjective responses to NT evaluated by EUS (comparison of uT and yuT and uN and yuN with OS and DFS). RESULTS: EUS staging detected metastasis that went undetected by computed tomography in 16% of metastatic patients. The accuracy between EUS after NT and postoperative pathological findings was 44.4% (34.2%; 54.7%) for T stage and 49.3% (37.5%; 61.1%) for N stage. On multivariate analysis, OS had significantly correlated with the objective response to NT. In the case of a response to NT, the median OS was 64.77 months, and in the case of stable disease, the median OS was 22.9 months (P = 0.01). CONCLUSION: EUS after NT can be used for staging. Despite its moderate accuracy, the evaluation of the response to NT by EUS seems to be correlated with patient prognosis.