Tumorigenesis and prognostic factors in colorectal carcinoma with regard to tumor localization

The rising incidence of colorectal carcinoma, particularly in the industria l nations of Europe and USA, directs the attention to the aetiological fact ors of these tumors: nutrition, the association with colorectal adenoma, fa miliary genetic disorders as familiar adenomatous polyposis and hereditary non polyposis colorectal cancer. Some aspects of molecular biology are disc ussed. Furthermore, right and left part of the colon (divided by the Cannon -Boehm point) and the neoplasms of these sections of the colon are differen t in embryology, function and morphology. The cancers of the right colon de velop without polypoid changes, those of the left part in majority via the adenoma-carcinoma sequence. It is possible to demonstrate differences betwe en these two localizations in the DNA-content (diploid tumors on the right side), in the lost of allels (especially distal tumors), in proliferation a ctivity (lower in right side tumors) and in the expression of oncofetal ant igens. Besides, there are some histological differences between neoplasms o f the right and left colon (production of mucin,,,Crohns like lymphoid reac tion", histological grading). In our own material of 262 patients with rese cted colon carcinoma we have investigated the distribution of carcinoma in the right and left colon, furthermore the T-classification, histological gr ading and the proportion of mucinous carcinoma in the different tumor local izations.