INTRATUMORAL REGIONAL HETEROGENEITY OF DNA-PLOIDY PATTERNS IN COLORECTAL CARCINOMAS

There is no agreement on the evaluation of intratumoral DNA ploidy het erogeneity, and its clinical significance remains controversial. We ca tegorized intratumoral ploidy heterogeneity in an effort to avoid conf usion and misunderstanding among investigators. We classified the hete rogeneity into 3 major types (Types A, B and C) and a combined type (T ype D), based on the intratumoral distribution profiles of DNA aneuplo id lines identified by flow cytometry in 52 cases of colorectal cancer with intratumoral DNA ploidy heterogeneity selected from a consecutiv e series. Every carcinoma examined in this study fell into one of the 4 categories: Twenty-six tumors (50%) were classified as Type A, 6 (11 %) as Type B, 2 (3%) as Type C, and Is (36%) as Type D. We discussed t he mechanisms of DNA ploidy heterogeneity evolution within a tumor, an d also proposed a pathway to these types of DNA ploidy heterogeneity a s an aid to understanding the relationship between tumor progression a nd DNA ploidy changes.