부산대학교 도서관

Differences between the types of genetic changes associated with cancers at two different sites within the gastrointestinal system are evaluated. Many genetic changes have been implicated as possible causative factors in the formation of cancers. However, the sequence of biological events and the individual mechanisms behind these pathologic genetic changes are largely unknown. Three types of genetic changes have been found in cancers of the junction of the colon and rectum (colorectal carcinomas), including changes in DNA content, loss of genetic information (deletions of genes or portions of chromosomes) and activation of gene locations which cause cancer (oncogene). After examining human cancerous tissue for genetic change and correlations between the genetic variations and type and location of the cancer, it is concluded that in tumors located towards the end of the colorectal area, changes are usually of the deletion type and abnormalities include problems of mitosis (cell division). Such differences in the genetic patterns in tumors affecting these areas support the notion that the underlying genetic mechanisms of tumor production (pathogenesis) may also be different.