Gastric precancerous lesions: heading for an international consensus.

As pathological criteria lie at the foundation for the classification of many diseases, a crucial requisite for such classifications to be valid is that their morphological basis be standardised. Inadequately standardised diagnostic criteria result in unacceptable interobserver variation, a factor that may influence both individual patient care and the evaluation of clinical protocols. One of the most important goals in gastric diseases today is to establish whether cure of Helicobacter pylori is an effective preventive measure against gastric cancer. To tackle this issue it is necessary to measure reliably intermediate outcomes, specifically gastric atrophy and dysplasia. However, there is little agreement on what gastric atrophy and atrophic gastritis are, and treatment and follow up results obtained at one clinical centre are often radically different from those obtained at another. Similarly, studies that examine the fate of dysplastic lesions in the stomach show a great divergence of outcomes between Europe and North America and Japan, where the concept of dysplasia has different connotations. To reach a consensus on the definitions and diagnostic criteria for atrophy and atrophic gastritis, a group of gastrointestinal pathologists and gastroenterologists met in Houston, Texas, USA, in February 1998. Substantive progress was made, but several problems remained, and a study aimed at resolving the issues that seem to stand in the way of an international agreement is currently underway. To fulfil the need for a broad discussion on the diagnostic differences of gastric dysplasia and cancer between East and West, an international group of pathologists gathered in Padova, Italy, in the spring of 1998. Their main objectives were: (1) to agree on the definitions of the spectrum of gastric preneoplastic lesions; (2) to establish an international glossary for gastric precancerous lesions; and (3) to test the consensus and eventually generate guidelines useful to clinicians for the development of management strategies. A consensus was achieved on the definition of gastric dysplasia as preinvasive neoplasia. Other validation studies are underway. The experiences achieved in the search for an international consensus on the phenotypes of atrophic gastritis and gastric dysplasia may represent a model in dealing with the new scenario of a modern evidence-based pathology.