THE PROGNOSTIC-SIGNIFICANCE OF DNA FLOW-CYTOMETRY IN BREAST-CANCER - RESULTS FROM 881 PATIENTS TREATED IN A SINGLE-CENTER

In this single-centre study of 881 patients, S-phase fraction (SPF) wa s shown to be a significant prognostic marker in terms of overall surv ival (OS), relapse-free survival (RFS) and survival after relapse (SAR ). Further, SPF had independent prognostic significance when consideri ng a range of other clinicopathological variables, namely tumour grade and stage, nodal status, patient age, tumour size, menstrual status a nd treatment details. For OS and RFS, SPF was the second strongest pre dictor of the clinical course of the disease after nodal status, and f or SAR it was the strongest prognostic marker. SPF correlated positive ly with histological grade but was the stronger predictor of survival. The distribution of SPF values was markedly different for the two plo idy classes of tumour, with DNA aneuploid tumours having a significant ly higher average SPF. However, SPF retained its independent prognosti c ability when DNA diploid and aneuploid tumours were analysed separat ely, DNA ploidy itself also proved to be an independent prognostic mar ker but the survival difference between the two ploidy classes was muc h less than that seen for different levels of SPF. Tumours with severa l DNA aneuploid populations (multiploid tumours) tended to have a wors e prognosis than other aneuploid tumours but this trend did not reach statistical significance. In this and other studies from this centre, SPF has proved to be a robust predictor of clinical outcome in carcino ma of the breast.