PROBLEMS ARISING FROM EASTERN AND WESTERN CLASSIFICATION SYSTEMS FOR GASTROINTESTINAL DYSPLASIA AND CARCINOMA - ARE THEY RESOLVABLE

It has become increasingly apparent that the Japanese and Western syst ems of classifying dysplasia and carcinoma in the gastrointestinal tra ct are not the same. The implication of these differences is that in a n article in a Western journal on gastrointestinal 'cancer' originatin g from Japan, it is often impossible to repeat the study to confirm or refute it, because of these differences in definitions. Although ther e is no reason why it should not be just as much of a problem if Weste rn research is published in Japanese journals, this is currently not a major problem. The terminological differences do not mean that one is right and one wrong; they are simply different. We had an opportunity to look at these differences in detail in a series of 100 gastric bio psies. In this review we outline these differences and indicate the si milarities, differences and problems between these two systems. 'Carci noma' is diagnosed in Japan by virtue of its structural and cytologica l features, but by invasion in the Western system. Adenoma does not me an a dysplastic lesion in the Japanese system (although it can) but in most cases is similar to low-grade dysplasia irrespective of the macr oscopic/endoscopic appearances (hence flat and depressed adenomas in t he Japanese system); however, most examples of high-grade dysplasia in the Western system, as well as some low-grade dysplasia, becomes 'can cer' in the Japanese system. Conversely, both have conceptual areas th at are useful in the other's system. Because we were ultimately able t o use each other's systems, we were able to show where these systems c ome together and diverge. These provide hope that a common classificat ion encompassing both systems that allows communication between both s ystems is feasible.