Flow cytometric DNA analysis as prognostic factor in human breast carcinoma

Fresh tumour tissue from 198 primary invasive breast carcinomas was analysed by DNA flow cytometry. 108 tumours were non-diploid. A significantly higher proportion of non-diploid tumours was found among node-positive patients, patients with oestrogen receptor negative tumours and among patients with ductal carcinomas. The survival of patients with diploid and non-diploid tumours was not significantly different (p = 0.1). Totally, 145 tumours were analyzed with respect to S-phase fraction (SPF). The distribution of SPF was different in diploid and non-diploid tumours. A low SPF group, defined as the lower SPF quartile (< or = 4.6% in diploid and < or = 8.5% in non-diploid tumours), was associated with highly differentiated tumours and oestrogen receptor positive tumours. Histological grading revealed a highly significant correlation to SPF. 57% of ductal carcinomas grade I (8 out of 14), 30% of ductal carcinomas grade II (20 out of 67) and 5% of ductal carcinomas grade III (2 out of 37) had a low SPF. Patients within the low SPF group had a significantly longer survival than had patients within the high SPF group (p = 0.006). In a multivariate analysis the SPF was found to be an additional prognostic factor next to node status and ER status.