Abstract
According to “General Rule for Clinical and Pathological Record of Colorectal Cancer”, 33 poorly differentiated adenocarcinomas of the colon and rectum among 569 resected colorectal cancers were clinicopathologically studied, comparing to the most common 355 well differentiated adenocarcinoma. Poorly differentiated adenocarcinomas represented as low as 5.8% of all cancers. When compared to well differentiated adenocarcinomas, poorly differentiated ones were more frequently found in the colon, especially remarkable in the right side, and macroscopically those predominantly included infiltrating ulcer types. Hepatic metastasis was found in a rate of 21.2%; lymph node metastasis, 66.7%; and 27.2% of positive lymph nodes were of the 3rd group of lymph nodes. Invasion depth of s (a2) and si (a1) were found in 81.8%; lymph vessel invasion in 97%; and venous invasion was positive in 87.9%. Compared to well differentiated adenocarcinomas, poorly differentiated adenocarcinomas showed significantly high rates in all items, namely, poorly differentiated adenocarcinomas were in more advanced stages such as stage IV and V. Curative resection rate was as low as 54.5%. Five-year survival rate was also low (38.4%) in all 33 cases, but was 59.6% in curative resection cases, that did not significantly differ from 75.1% in well differentiated adenocarcinoma cases.
