Perioperative EOX treatment in operable locally advanced gastroesophageal adenocarcinoma: Prediction of tumor response by FDG -PET and histopathology.

PURPOSE

The aim of this retrospective single-center analysis was to evaluate the feasibility of fluorine-18 fluorodeoxyglucose (FDG)-PET imaging in evaluating metabolic response of preoperative chemotherapy in the treatment of locally advanced operable gastroesophageal adenocarcinoma and to investigate the association between histopathologic and FDG-PET response and overall survival.

METHODS

Patients with locally advanced adenocarcinoma of distal esophagus, gastroesophageal junction or stomach were assessed for the study during 2008-2012. After evaluation with endoscopy, computed tomography and FDG-PET, patients with clinical stage II or III disease were assigned for perioperative EOX (epirubicin-oxaliplatin-capecitabine) treatment targeted at three cycles both pre- and postoperatively, if possible. Metabolic response was evaluated by repeated FDG-PET during or right after the second chemotherapy cycle. Becker tumor regression grade (TRG) was used to evaluate histopathologic response. For statistical purposes, the clinically significant cut-off for tumor maximum standardized uptake value (SUV) change (SUVδ%) was set at -35%.

RESULTS

54 patients were included in the study. 53 PET images were obtained before chemotherapy, 11 (21%) of those were PET negative. A major metabolic response was detected in 19 patients and major histopathologic response in 14 patients. No statistically significant association was observed between SUVδ% and histopathological responses. Median overall survival (OS) time of the patients was 49.9 months. No association between OS and PET response was found in our study. The administration of all six cycles of perioperative EOX was associated with improved OS.

CONCLUSIONS

Follow-up PET during or right after second preoperative chemotherapy cycle did not assist in identifying patients with favorable histopathological response or OS.