IntroductionThis year's Digestive Disease Week (DDW) saw the presentation of more than 70 studies focusing on endoscopic diagnosis and treatment of precancerous conditions and tumors in the upper gastrointestinal tract. For reasons of space, only a handful of these are discussed in detail in this review [1 ± 9]; the remaining are summarized in tabular form or simply mentioned in the text. The selection process was facilitated by the fact that the majority of studies were single-arm and retrospective ± prospective or comparative studies, quite apart from randomized trials, were notable exceptions. Endoscopic diagnosis and treatment of Barrett's esophagus were covered in a separate DDW report [10].
Innovations in Endoscopic DiagnosisResearch in this field focused on Barrett's esophagus, with only a few studies on other topics being presented. Among the other topics, the microvascular pattern of the gastric mucosa appears to attract most attention. The idea is that local changes in the size, shape, and distribution of capillaries may be predictive of the histology. The examination technique involves magnification endoscopy, either alone or in combination with the use of a modified light source (narrow-band imaging [NBI] endoscopy), or with spraying the mucosa with epinephrine solution (pharmacoendoscopy). There is still only preliminary experience in this area, but the findings appear to be encouraging.Yao et al. prospectively evaluated 161 flat reddened gastric lesions, corresponding either to cancer (n = 38) or gastritis (n = 123) on histology, for the presence of various predefined abnormalities in microvascular pattern, as observed on magnification endoscopy [1]. One of the features evaluated, namely the ªproliferation of microvessels irregular both in shape and distributionº, was present in 97.4 % of cancers (95 % CI, 92.3 ± 100 %) and in only 0.8 % of gastritis lesions (95 % CI, 0 ± 2.4 %). The sensitivity and specificity for cancer detection based on this feature were 97.4 % and 99.2 %, respectively. The study included only well-differentiated cancers, because ± as shown in a previous work by the same group ± early undifferentiated cancers are usually pale and produce a nonspecific image on magnifying endoscopy [11]. Another small study (including 13 patients) suggested that abnormalities in the microvasculature may be enhanced by spraying the surface of the lesion with epinephrine solution followed by indigo carmine dye. This appears to work, but only in the elevated type of early gastric cancer and not in the depressed lesions [12].NBI endoscopy involves using light with modified spectral features to enhance details of the microcapillary and mucosal pattern on magnification endoscopy. Again, the ultimate goal is to predict the histology without obtaining a biopsy. Sharma et al. compared the findings on NBI endoscopy with the histology results in 54 patients with normal mucosa or with various degrees of chronic gastritis [2]. In normal mucosa and mild chronic gastritis, the capillaries had a normal size, sha...