P-0007 Accuracy of Endoscopic Ultrasound Examination in Preoperative Staging of Oesophageal Cancer: Results from a Referral Centre for Oesophageal Cancer.

Abstract

ABSTRACT Introduction Endoscopic ultrasound (EUS) has been regarded as the most accurate staging tool in the diagnosis of oesophageal cancers. Staging results have a strong impact on the decision as to whether a patient should undergo endoscopic treatment, surgery alone, or neoadjuvant therapy. This retrospective study of the data collected prospectively was conducted to analyze the accuracy of oesophageal cancer staging using EUS. Methods All patients who received EUS for staging of oesophageal cancer before oesophagectomy from January 2009 to December 2010 at a tertiary care centre were included in the study. Endoscopic ultrasound staging for these patients was compared against the post-operative pathological staging, in order to identify the accuracy of the endoscopic staging process. Results 156 consecutive patients underwent oesophagectomy and 106 of them had EUS examination (mean age 68 +/- 14 years; 92 males, 14 females). Majority (n=92) had adenocarcinoma and 14 had squamous cell cancer. 81 of 106 had undergone surgery after EUS staging. 21 had EUS staging done above the tumour due to stricture and 9 had EUS after dilatation before staging. Postoperatively, 1 had T0 (1.2%), 9 were staged as having T1 cancers (11%), 12 had T2 (14.8%), 56 had T3 (69%), and three patients T4 (4%) lesion. The overall accuracy for EUS in identifying the correct T stage was 75%. Accuracy of EUS for T1 stage was 67%, for T2 was 67%, for T3 was 89%. Both T1 and T2 cancers were over-staged. Positive lymph nodes were diagnosed in 42 patients (53%). The accuracy of EUS for staging the lymph node disease was 69% for N0 disease, 56% for N1 disease respectively. EUS staging done above the tumour had an accuracy of 90% and for those that had dilatation before staging 77% for T staging and 67% for N staging in both the groups. Conclusion The diagnostic accuracy of EUS in patients with oesophageal cancer remains variable. Both T1 and T2 cancers were frequently over-staged, with a significant effect on the subsequent treatment strategy. Additionally, dilatation of the stricture is likely to reduce the accuracy of T staging by under-staging the disease. This study highlights important limitations of endoscopic ultrasound for staging of oesophageal cancers, which requires important consideration and further review.