New approaches to gastric cancer staging: Beyond endoscopic ultrasound, computed tomography and positron emission tomography

Abstract

Currently, there is no single gold standard modality for staging of gastric cancer and several methods have been used complementarily in the each clinical situation. To make up for the shortcomings of conventional modalities such as endoscopic ultrasound, computed tomography and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography, numerous attempts with new approaches have been made for gastric cancer staging. For T staging, magnifying endoscopy with narrow-band was evaluated to differentiate mucosal cancer from submucosal cancer. Single/double contrast-enhanced ultrasound and diffusion-weighted magnetic resonance imaging were also tried to improve diagnostic accuracy of gastric cancer. For intraoperative staging with sentinel node mapping, indocyanine green infrared and fluorescence imaging was introduced. In addition, to detect micrometastasis, real-time reverse transcription-polymerase chain reaction system with multiple markers was studied. Staging laparoscopy using 5-aminolevulinic acid-mediated photodynamic diagnosis and percutaneous diagnostic peritoneal lavage were also evaluated. However, most studies reporting new staging methods is preliminary and further studies for validation in clinical practice are needed. In this mini-review, we discuss new progress in gastric cancer staging. Especially, we focus on new diagnostic approach to gastric cancer staging beyond the conventional modalities and briefly review the remarkable clinical results of the studies published over the past three years.

Keywords: Gastric cancer; Neoplasm staging; Diagnostic accuracy; New methods; New approaches

Core tip: Currently, there is no single gold standard modality for staging of gastric cancer. To make up for the shortcomings of conventional modalities or to replace these traditional methods, numerous attempts with new approaches such as magnifying endoscopy with narrow-band imaging, single/double contrast-enhanced ultrasound, and diffusion-weighted magnetic resonance imaging have been made for gastric cancer staging. In addition, for intraoperative staging, several newer methods associated with sentinel node mapping and diagnostic laparoscopy have been studied. However, most studies reporting new staging methods are preliminary and further studies for validation in clinical practice are needed.