Endoscopic ultrasound in restaging and predicting pathological response for advanced gastric cancer patients after neoadjuvant chemotherapy

Aim To evaluate the role of endoscopic ultrasound (EUS) in restaging and predicting response after neoadjuvant chemotherapy in patients with advanced gastric cancer. Methods In all, 48 advanced gastric cancer patients were recruited from June 2007 to December 2010 after providing their written, informed consent. All patients underwent an EUS before and after three cycles of neoadjuvant chemotherapy (FOLFOX 6), and then a radical resection was performed 3-4 weeks after chemotherapy. The results of EUS were compared to the pathological results of the resected specimens. Results After chemotherapy, the overall sensitivity of EUS for T classification was 63 percent (T2: 44%, T3: 68%, T4: 90%), and overstaging (31%) was more frequent than understaging (6%). The sensitivity and specificity of EUS for N classification were 56 and 50 percent, respectively (N0: without lymph node metastasis, N1: with lymph node metastasis), with 15 percent overstaged and 32% understaged. EUS revealed that T and/or N downstaging occurred in 46 percent (22/48) of patients after chemotherapy, most of whom had a favorable pathological response to the chemotherapy compared with other patients without T and/or N downstaging. No T or N upstaging was observed after neoadjuvant chemotherapy. Conclusions The accuracy of restaging by EUS for T and N classification was not as good as pathological data for locally advanced gastric cancer patients after neoadjuvant chemotherapy. However, T and/or N downstaging confirmed by EUS correlated well with the degree of pathological response to chemotherapy.