Gastric epithelial dysplasia: the Western perspective.

The need for early diagnosis of gastric cancer is emphasized by the fact that gastric cancer remains the second most common cause of cancer related deaths worldwide. The aggressive surveillance and definite therapy for low and high-grade dysplasia, which can be achieved endoscopic means, remains the cornerstone of clinical management. Although the precursor status of dysplasia is not contested, its classification is controversial and fraught with marked inter-observer variations. Most cases of gastric dysplasia have an "intestinal" phenotype referred to as adenomatous dysplasia. Hyperplastic (type II dysplasia) is another less common variant. The progression of dysplasia to carcinoma is paralleled by a stepwise accumulation of multiple, but yet uncertain, genetic abnormalities. There are no immunohistochemical or molecular assays that can stratify with certainty the risk of progression to cancer. Given the low rate of transformation of low-grade dysplasia, annual endoscopic surveillance with re-biopsy is advocated. A diagnosis of indefinite for dysplasia should also prompt endoscopic surveillance. A diagnosis of high-grade dysplasia is more ominous, since it progress to cancer in most cases. However, the novel imaging and endoscopic modalities have modified management strategies with mucosal lesions amenable to endoscopic resection, while surgical resection is reserved to invasive adenocarcinoma with submucosal invasion.