Endoscopic ultrasound in cancer staging

Background: Endoscopic ultrasound (EUS) represents one of the most significant developments in endoscopy over the past 20 years. It allows highly detailed assessment of the gastrointestinal wall layers as well as to visualize extraluminal structures such as the mediastium and retroperitoneum. Methods: The literature was reviewed to assess the role of EUS in cancer staging. Results: EUS is an integral part of the staging of many upper gastrointestinal cancers as well as rectal and lung cancer and has been shown to be cost-effective. It can be used to confirm malignancy in suspicious lesions as well as to identify and confirm nodal or metastatic spread. It has been used to re-stage cancers following chemoradiotherapy, but results are disappointing. Future developments are discussed, which may include using EUS-guided delivery of anti-tumour agents directly into tumours.