Narrow band imaging endoscopy for detection of precancerous lesions of upper gastrointestinal tract.

Gastric cancer (GC) is an important health problem despite the advances in surgery and chemotherapy and although the incidence is decreasing, GC is still considered the second most common cause of deceases produced by cancer. Survival rates in gastric cancer are low, mainly because most patients are often diagnosed in late stages. The current interest in the diagnostic of GC is the detection of early gastric cancer. Advances in high-resolution endoscopic techniques such as narrow band imaging (NBI) allow the detection of early precancerous lesions like polyps or metaplastic mucosa. Performing only white light imaging endoscopy in order to detect gastric cancer can lead to omission or misdiagnose of a considerable number of early gastric cancers. NBI endoscopy associated with other high-resolution examinations is viable in detecting early gastric cancer, though few studies also indicate that the endoscopist's expertise plays an important factor as well.