Early diagnosis of digestive tract neoplasms is beneficial for maximising the possibility of cure. The diagnostic efficacy of conventional endoscopy is currently limited. Confocal laser endomicroscopy (CLE) can magnify tissue to the cellular level, which is beneficial for endoscopic biopsy. Currently, its clinical application has attracted wide interest among endoscopists. Many studies have explored its application potential in the early diagnosis of digestive tract tumours. This paper reviewed a large number of clinical studies on CLE in early esophageal and gastric cancers, providing more evidence-based support for endoscopists in making clinical decisions.

Esophageal and gastric cancers are common diseases with high morbidity and mortality; thus, early detection and treatment are beneficial to improve prognosis. Confocal laser endomicroscopy (CLE) is a novel imaging technique that permits the histological analysis of tissues during endoscopy. CLE has been shown to uniquely affect the diagnosis of early upper gastrointestinal cancers. Relevant literature was searched using PubMed and Google Scholar databases. Despite inherent flaws, CLE can reduce tissue damage and improve diagnostic accuracy to a certain extent. CLE in combination with other imaging methods can help enhance the detection rate and avoid unnecessary biopsies in the management of esophageal or gastric cancer and precancerous lesions. CLE is of great significance in the diagnosis and surveillance of early cancers of the upper gastrointestinal tract. Further technical innovations and the standardisation of CLE will make it more responsive to the needs of routine clinical applications.