Accuracy of Endoscopic Ultrasound After Neoadjuvant Chemotherapy in Locally Advanced Esophageal Cancer

Abstract

Background: After combined radiation and chemotherapy, the accuracy of EUS for tumor and nodal staging appears to decreases because of the difficulty in distinguishing persistent tumor from fibrosis and inflammation within the esophageal wall or lymph nodes. Most studies have reported on EUS after combined chemorads but the accuracy of EUS after neoadjuvant chemotherapy is not well described. Aim: Determine the accuracy for tumor and nodal staging in patients with locally advanced EC after neoadjuvant with chemotherapy. Methods: EUS data from prospective neoadjuvant chemotherapy trial in locally advanced EC was reviewed. Patients underwent chemotherapy protocol with FUDR, Leucovorin, Paclitaxel and Cisplatin. All patients had pre- and post-chemo EUS. Only patients that underwent surgery were included. Surgical pathology stage was compared with EUS staging post-chemotherapy (AJCC TNM stage). Maximum tumor thickness was measured pre- and post-chemotherapy under radial EUS. Results: From 1999 through 2004, thirty-six patients were identified (32M and 4F); mean age 65 yrs. Thirty-four had adenocarcinoma and two squamous. All patients had gastroesophageal junction tumors except for two patients with mid-esophagus squamous tumors. Initial T staging were: 32 patients with T3 and four patients T2 lesion. On pre-treatment EUS, six patients (17%) had significant tumor stenosis that prevented exam of the entire tumor. On EUS post-chemo; only one patient still had significant esophageal stenosis. The tumor (T) and lymph node (N) stage accuracy after chemotherapy were respectively: 64% (23/36) and 61% (22/36). The most common EUS errors post-chemotherapy were overstaging (T2-T3) in 8 out of 13 patients (61.5%) and nodal disease (N0-N1) in 8 out of 14 patients (57%). A wall thickness of 11 mm or more post-chemotherapy provided the best accuracy for differentiating T3 from T1-2 tumors. The accuracy to differentiate stages I/II from stage III post-chemo was 72% (26/36). Conclusion: Considering that distinguishing between T2 and T3 EC is challenging after neoadjuvant therapy. EUS staging accuracy after chemotherapy in EC is good but lower than reported for pre-treatment staging. Overstaging is the most common error in re-staging after chemotherapy. Studies using EUS combined with fine-needle aspiration biopsy and other imaging modalities are needed in EC to determine if EUS post-neoadjuvant therapy can predict survival or better select patients for surgical resection.