Staging and preoperative evaluation of upper gastrointestinal malignancies

Abstract

Esophageal and gastric cancers are distinct carcinomas of the upper gastrointestinal tract, although the distinction between them becomes less clear at the gastroesophageal junction (GEJ). Increasingly accurate staging is possible based on newer radiographic and surgical techniques such as positron emission tomography (PET), laparoscopy and thoracoscopy, laparoscopic ultrasound, and endoscopic ultrasound (EUS). For both cancer types, tumor classification is determined by depth of penetration of the primary tumor into the gastric or esophageal wall. For esophageal cancer, primary tumor anatomic position-upper, mid, and lower esophagus-is used to define the local nodal basin. Metastases in nodes outside the local basin are considered to be distant (M) rather than regional (N). In gastric cancer, the region of nodal metastasis has been abandoned in favor of the number of lymph nodes containing metastasis, which predicts outcome more accurately-patients with more than 15 positive lymph nodes have an outcome comparable to those with M disease. Increasing consideration is being given to the subclassification of tumors near the GEJ into types based on anatomical position, although this staging scheme ("Adenocarcinoma of the EsophagoGastric junction" or AEG type) has not yet been universally adopted. We review the current pathologic staging systems for esophageal and gastric cancers, the clinical staging approaches for these diseases, and the controversy surrounding classification of tumors of the GEJ.