CYTOKINETIC INVESTIGATIONS IN HUMAN BREAST-CANCER BY FLOW CYTOMETRICALLY RECORDED DNA-PROTEIN DISTRIBUTIONS

This prospective study characterizes T1-T2 breast carcinomas (N = 114) and fibroadenomas (N=16) by cell kinetic parameters derived from flow cytometrically recorded DNA/protein histograms. Ploidy level, cell cy cle distribution and the number of cell subpopulations (SP) characteri zed by correlating DNA and protein values were assessed. The subpopula tions were derived from the three-dimensional plot. The estrogen recep tor (ER) status was determined biochemically (N = 61). Within the G1/0 cell peak 1-6 SP were evident in principle. Depending on the number o f SP, two subsets were established: subset 1 with less than or equal t o 2 SP, subset 2 with greater than or equal to 3 SP. They differed sig nificantly in proliferative activity expressed in the percentage of ce lls in the G2M phase. Subset 2 showed the higher activity. Analysis of subset distributions revealed that subset 1 prevails in favourable pr ognostic cases as ER positive cases (P < 0.03), lobular carcinomas (P < 0.01) and LN- cases (P < 0.03), whereas subset 2 prevails in the unf avourable counterparts. Analysis of variance showed that the main effe ct on proliferative activity indicated by G2M% is due to subpopulation composition rather than histologic type, nodal status or ER status (P < 0.01, P < 0.002, P < 0.05), not even due to ploidy level (P < 0.000 1). The rationale for subset stratification may be cytogenetic variabi lity connected with protein content heterogeneity accounting for kinet ic SP.