PROGNOSTIC RELEVANCE OF METABOLIC RESPONSE TO NEOADJUVANT CHEMOTHERAPY FOR ADENOCARCINOMA OF T HE ESOPHAGU S AN D ESOPHAGOGASTRIC JUNCTION

Background: The prognostic value of the metabolic response to neoadjuvant therapy in patients with adenocarcinoma of the esophagus and esophagogastric junction (EAC) remains controversial. The aim of our single-center prospective trial was to evaluate the association of metabolic tumor and nodal response, as measured by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT), with disease-free survival (DFS) in patient with EAC treated with neoadjuvant chemotherapy (NAC) followed by surgery. Methods: Following the PET response criteria in solid tumors (PERCIST 1.0), PET/CT was performed before and after the third cycle of triplet N A C (epirubicine, cisplatina and 5-fluorouracil or capecitabine). The relative changes of the maximum, peak and mean standardized uptake value (ASULmax, ASULpeak, ASULmean), metabolic tumor volume (AMTV) and total leasion glycolysis (ATLG) in the primary tumor and ASULma x in the regional lymph nodes were analyzed in terms of prediction of DF S using Cox regression analysis. Results: Some 94 patients with surgical resection were included between 2009 and 2015. Of the tumor metabolic response parameters, only ATLG and AMT V were associated with survival. Stepwise cutoff analysis found ATLG>45% best predicted DF S (HR 0.25, p = 0.0018). Persistens of FDG - avidity of lymph nodes after NA C was associated with worse DF S (HR 2.63, p < 0.001). Multivariable analysis of preoperative variables (baseline characteristics and metabolic response) showed that only tumor ATLG>45% and post-NAC nodal FDG-avidity were predictors of DFS. In the final multivariable model including postoperative variables, pN-stage and postN A C nodal FDG-avidity remained the only independent variables associated with DFS. Conclusion: ATLG is the most optimal metabolic parameter reflecting the response to NA C in the primary tumor, however it did not independently predict DF S after surgery. The complete metabolic response in the lymph nodes after NA C independently predicted the prognosis. .