1. Personal Views on the Definition of Early Cancer in the Large Intestine

Abstract

During the years from 1964 to 1973, there were 37 cases of mucosal (m) or submucosal (sm) cancer among 820 cases of single colonic or rectal cancer of curative resection found in the Cancer Institute Hospital, Tokyo. Of these 37 cases, 19 were mucosal and 18 were submuosal cancer, and lymph nodes were involved in only one of submucosal cancer cases. In these 37 cases, 13 tumors were larger than 2.0cm in superficial extension. The pedunculated, protruded, or elevated type is characteristic for mucosal and submucosal cancer of the large intestine. The 5-year survival rate in these 22 cases was 100%.The Dukes A group accounted for 17.8% of the cases of curative resection and their 5-year survival rate was 93.6%. The Dukes A might be designated as early cancer but this classification is surgicopathological, and clinical discrimination of the Dukes A is quite difficult.Clinical measurement of the size of a tumor is quite simple. Tumors of 2.0cm or less in diameter are mostly mucosal and submucosal cancer, and 5-year survival of patients with such a cancer is 100%. Tumors larger than 2.0cm are not found infrequently in mucosal and submucosal cancer, and patients with such a cancer show a good prognosis.Mucosal and submucosal concer should be diagnosed histologically but clinical assumption is also possible. Designation of mucosal and submucosal cancer is appropriate for the standard of early cancer of the large intestine, bun cases showing the presence of clinical metastasis should be excluded from early cancer.