Endoscopic Ultrasound Staging of Gastric Cancer after Neoadjuvant Chemotherapy with Flot Regimen

Background: Gastric cancer is one of the most common malignant tumors in the gastrointestinal tract. Neoad-juvant chemotherapy may be administered as a means of “downstaging” a locally advanced tumor prior to curative resection. Perioperative chemotherapy with FLOT regimen (florouracile, leuvocorin, oxaliplatin, docetaxel) has shown to improve overall survival in patients with advanced gastric cancer (AGC). The aim of our study was to evaluate the endoscopic ultrasound (EUS) accuracy of T and N staging of AGC compared with surgical specimen after FLOT. Methods: We retrospectively analyzed 29 patients with AGC, who had their preoperative TNM staging with EUS and computer tomography (CT) and who underwent neoadjuvant chemotherapy with FLOT. Then patients were evaluated with a second EUS and CT to determine eventual downstaging. EUS staging was compared with post surgical pathology used as gold standard. Results: At eus evaluation downstaging of tumor depth (T) alone was observed in 8 patients (27,6%), of nodes involvement (N) alone in 6 patients (20,7 %), and both in 3 patients (10,3%); at CT exam the downstaging occurred only in 11 patients out of 29 (38%). The overall accuracy of preoperative T and N staging by EUS was 68.75% (95%CI 41.34-88.98) and 81.25% (95%CI 54.35-95.95) when compared to the postoperative histopathological staging. Conclusions: Our results showed that EUS-based AGC restaging after FLOT regimen has an adequate diagnostic accuracy on T (68.75%) and N (81.25%). In order to identify which patients could have a beneficial response from FLOT regimen, EUS appears one of the best tool to have a precise evaluation of post chemio pre-surgical patient status.