GEOGRAPHIC-DISTRIBUTION OF CODOMINANT DNA STEMLINES IN BREAST-CARCINOMA

Breast carcinomas often contain multiple DNA stemlines in flow cytomet ric DNA histograms, However, due to mixing during tissue disaggregatio n the microanatomical relationship between the cells which comprise di stinct stemlines is unclear, We performed image cytophotometric DNA an alysis (IA) on two separate areas of intact tissue sections of 19 brea st carcinomas which were selected on the basis of flow cytometric (FCM ) DNA content heterogeneity (i.e., multiple stemlines), For comparison , similar analyses were performed on seven tumors with unimodal FCM DN A histograms, Six of the 7 tumors (86%) with unimodal FCM histograms w ere also unimodal in both IA DNA histograms, Among tumors with heterog eneous FCM DNA histograms, the presence of multiple stemlines was conf irmed in IA DNA histograms in 16/19, In nine of these 16 cases, multip le DNA stemlines having similar DNA indices were present in both areas of neoplasm examined with IA. The remaining seven cases displayed uni modal IA histograms in both areas, however DNA indices differed betwee n the two histograms, These findings imply that cell populations corre sponding to now cytometrically detected DNA stemlines are often intima tely admired, even within geographically separated portions of breast tumors, This pattern suggests that productive interactions between gen etically distinct tumor populations may lead to stable co-dominance of ancestral clones during progression of some breast carcinomas. (C) 19 95 Wiley-Liss, Inc.