In order to elucidate the relationship between stomach cancer and gastritis the histopathologic changes of the mucosa of stomach cancer were studied with special reference to cellular infiltration, intestinal metaplasia, mitotic rate of gastric mucosa, thickness of mucosal and glandular layer and the ratio of glandular layer to mucosal layer.
The tissue specimens from 16 cases of gastric cancer (3 cases of them being early gastric cancer), 3 cases of gastric ulcer, 4 cases of gastritis and one case of normal subject, to the total of 24 cases were selected for the present study.
The stomachs surgically removed were opened along the greater curvature for macroscopic observations and fixed in 10% formol solution. A number of specimens from 11 to 33 with average of 22 were prepared to cover the entire area of the resected stomach. The specimens were stained with the hematoxylin-eosin solution. Practically, the entire area of stomach was divided into 6 areas, namely, anterior, posterior wall and lesser curvature of fundus and pyloric area. The vicinity of the lesion was added to above 6 areas in case of gastric cancer and ulcer. The specimeus were taken from the areas as evenly as possible.
According to the extent of cellular infiltration and intestinal metaplasia the changes were classified into 0 Point 3 Points. The mitotic rate was determined by Teir's method. The measurements were carried out with the mitotic areas of the glandular tubules cut continuously from gastric pit to base of the gland and arranged perpendicular to muscularis mucosae. The rate was measured in the areas of gastric, pyloric and intestinal type gland in separate. The mitotic rate was expressed by the percentage of mitotic cells to the total cell count.
As for the thickness of the mucosal and the glandular layers, serial sections were cut from gastric pit to base of the gland. The measurements were made with the gastric and the pyloric gland arranged perpendicular to muscularis mucosae. The thickness between the surface of muscularis mucosae and the mucosal surface was taken as the thickness of the mucosal layer, and that of lamina propria excepting the gastric pit was taken as the thickness of the glandular layer. The ratio of the glandular layer to the mucosal layer was calculated by measuring the thickness from corresponding glandular layer to mucosal layer. The results of the measurment were as follows.
1. The cellular infiltration in gastric cancer was more intense than other stomach diseases. The entire resected specimens of the stomach cancer were given about 2 Points of the cellular infiltration in average. The specimens of stomach cancer having carcinoma focus in the area of the gastric gland revealed more intense cellular infiltration than the ones having the foci in the area of pyloric gland. Furthermore, the change was related to the stage of the disease, namely more intense cell infiltration was observed in the advanced cases of gastric canccr.
2. The incidence and the extent of intestinal metaplasia of gastric mucosa were highest in gastric cancer, notably in the area of pyloric gland. The intestinal metaplasia was not related to the depth of the gastric wall involved by carcinoma and the site of carcinoma foci.
3. The mitotic rate of both gastric gland and pyloric gland was proved to be equal between gastric cancer and other stomach diseases. However, in the resected specimens of stomach carcinoma the rate was higher in the area of pyloric gland than the area of gastric gland and it was least in the vicinity of the lesion.
4. The mitotic rate of intestinal type gland showed no difference between gastric cancer and other stomach diseases. In the resected specimens of stomach carcinoma having the carcinoma foci in the area of gastric gland showed a higher mitotic rate than those having the lesion in the area of pyloric gland.