[Natural history of gastric carcinoma viewed from growth patterns of early carcinoma].

Regarding the natural history of gastric malignancy, we arrived at the following conclusions. There are at least two types of gastric cancers: a rapidly growing type (Pen) and a slow growing superficial type (Super). It seems that the Super type early cancer progresses to a funnel shaped, non-Borrmann advanced type of cancer of a lesser incidence, and the Pen type leads to the most advanced cancer of Borrmann type. A slow growing Super type cancer is more likely to be detected because it remains at the early stage for a longer period. Conversely, the rapidly growing Pen type cancer is less likely to be detected until it has reached an advanced stage. Ulcer symptoms accompanying the Super type seem to create a detection bias, and the chance of detection is increased. A rough estimation of the occurrence rate of slow and rapidly growing cancer is 1:2 or 1:3. Considerable effort should be directed to studies on rapidly growing gastric cancer, and the early detection of Pen type cancer is of top priority. The focus of our inspection future should be directed to differentiation of "type oriented early cancer".