Keimyung Medical Journal, Vol.5(2) : 141-147, 1986
During the years 1974—1986, the authors had undertaken a study of multiple primary malignant tumors in Keimyung University Dongsan Hospital, Taegu. A total 40 cases of multiple primary malignant tumors were identified. Eleven cases of simultaneous primary multiple cancers Ave re in the alimentary tract (27.5%). Five eases out of eleven (45.4%) had associated with multiple or single adenomatous polyp in rectosigmoid except one in stomach. The rectosigmoid is the most common site for multiple primary cancers (45.4%), male to female ratio is 8 : 3， predominant in male, mean age 54.7 year.
It has been suggested that most human cancers occur both in a hereditary and non-hereditary form. In each case the tumors have been attributted to a multistage mutational process.
However the answer is that multiple primary cancers are certainly a pari: of the overall oncology problem. We have found that multicentricity of cancer may give us clues to both cancer etiology and cancer predisposition. It is "well known that adenomatous polyps are not only commonly associated with carcinoma and also arc often the site of malignant transformation which is clearly proved in this study, furthermore recent reports demonstrate that in study of operative specimens of cancers of the colon one or more adenomas vrere present in about one-third of patient, and in 75% of these, adenomas coexisted with two or more carcinomas (Morson and Day 1981). Possible implication of these findings were discussed and related literatures were reviewed.