Abstract
The case of multiple gastric cancer has tended to increase in number in recent years, clinically having many important problems such as how to make certain diagnosis of multiple lesions and how to avoid cancerous residue in surgical operation. Histopathologically, factors such as the surrounding mucosa in the development of cancer, multicentric development of cancer and fusion or unification of multiple lesions are of interest in studying the development and growth of gastric cancer. Using 49 cases of multiple cancer which met the criteria by Moertel et al. (4.4%) among 1, 116 cases of primary gastric cancer which we had resected in the past 26 years (1956-1981) as the subjects, we examined clinicopathological features, measured the size (area) of each lesion and the distance between lesions and studied the possibility of these lesions getting fused with one another to become a single lesion in the course of their development and growth and also what lesion is liable to get fused. Results obtained are as follows : The incidence of multiple cancer was higher in early cancer than in progressive cancer, for multiple cancer was 16 (7.0 %) out of 229 cases of early cancer and 33 (3.7 %) out of 887 cases of progressive cancer (P<0.05) . As indicated by the age distribution of 37-81 years (average: 61.6 years) and the male to female ratio of 2.3: 1, multiple cancer, compared with single cancer, tended to be found more in those of the advanced age and males. The number of lesions was 2 in 42 cases (87.8 %), 3 in 5 cases (10.2 %) and 4 in one case (2.0 %) . 43 cases with two lesions were used in the subsequent pathological study. As for the location of cancerous lesion, both the main and sub-lesions mostly belonged to areas A and M, while only 5 (5.8 %) out of 86 lesions belonged to area C. The mean value for the size of lesions measured by the MOP (manual optical picture analyzing system) was 1, 624.3±241.7 mm2 (Mean±S. E.) for the main lesion and 422.8±82.7 mm2 for the sub-lesion. When comparison was made of two groups namely, cases accompanying early cancer and those accompanying progressive cancer, both the main and sub-lesions were larger in the cases accompanying progressive cancer (P<0.005) . By the macroscopic type, the main and sub-lesions were of the same type in many of the cases accompanying early cancer, that is, 11 (73.3 %) out of 15 cases, while no fixed tendency was seen in the cases accompanying progressive cancer. By the histologic type, the proportion of differentiated type of cancer was high with 27 cases (62.8 %) for both the main and sub-lesions, and this tendency was stronger in the sub-lesions. The differentiated type/undifferentiated type ratio was 2.6 in the main lesion and 3.8 in the sub-lesion. By the surrounding mucosa of the lesions, many cases belonged to the intermediate zone with the main lesion 69.8 % and sub-lesion 74.4 %, and this fact suggested association between the intermediate zone and development of cancer. As for the mode of arrangement of the lesion, the oblique arrangement was found the most with 53.5 %, followed by the vertical arrangement with 25.6 % and the horizontal arrangement with 20.9 %. The distance between lesions in each arrangement was 46.0±6.3 mm, 27.0±7.4 mm and 22.9±8.5 mm respectively, the longest distance being in the oblique arrangement (P<0.05) .
