Evolution and pathology of colorectal carcinoma

Numerous clinical, epidemiological, histological and experimental observations favour the adenoma-carcinoma sequence. Metastases occur only after invasion of the submucosa. The elevated rate of synchronous lesions (carcinomas and adenomas) is emphasized. In the rule, lymphatic spread precedes distant metastasis. Typing and grading should be performed according to the rules of WHO. The present UICC staging system will be replaced by a new 4th edition 1987. Early carcinoma (limited to the submucosa) has an excellent prognosis and may be treated by limited procedures (polypectomy, local excision) in the most cases. The modern concept of histology- and stage-adapted cancer therapy requires the pre-, intra- and postoperative cooperation with the pathologist. (Author)