Back ground: Report on cancer incidence in Indonesia was presented in relative frequency. To lower the bias, the report has been presented in age standardized cancer ratio (ASCAR). The report was a department of pathology based cancer registration. The ASCAR of gastro intestinal cancer in Indonesia has some variation between pathologic centres. The incidence of rectal cancer in Jogjakarta was higher than colon cancer, and stomach cancer is very low. The risk factors of stomach cancer are H. Pylori infection and food consumption especially salt and the risk factor of colorectal cancer is food consumption. Purpose: The article will discuss the ASCAR of stomach and colorectal cancer in Indonesia. . The histopathologic of stomach and colorectal cancer in Jogjakarta will be presented from the view point of pathology. Method: Stomach and colorectal cancer data from 13 pathologic diagnostic centres in Indonesia were collected. The pathogenesis of stomach and colorectal cancer will be discussed in correlation with the cancer prevention. Result: The incidence of stomach cancer in many centres in the year of 1996 are very low from 0,00% - 0,24 % for the most lowest incidence and 2.22 % - 5.60 % for the highest incidence. The higher incidence of stomach cancer was in Medan 19 males (5.6%); 10 females (2.22%); Palembang 7 males (4.75%), 1 female (0.11%); Surabaya 18 males (1.38%), 7 females (0.35%); Denpasar 12 males (2.97%), 1 female (0.24%), and Jakarta 55 males (4%), 28 females (1.39%). The incidence of colorectal cancer is almost equal in every pathologic diagnostic centres. It is interesting that the incidence of rectal cancer was higher than colon cancer. In Jogjakarta the histopathological feature of stomach cancer was predominated by poorly differentiated adenocarcinoma, while colorectal cancer was predominated by well differentiated adenocarcinoma. Conclusion: The low incidence of gastric cancer in Indonesia in relation with H. Pylori and food consumption and the high ratio between rectal and colon cancer in correlation with the food consumption and it pathogenesis need further investigation.
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