Hypoploidy defines patients with poor prognosis in breast cancer.

The clinicopathological features currently used in breast cancer prognosis often fail to characterize the clinical heterogeneity of the disease accurately. Our study is aimed to investigate the predictive value of DNA flow cytometry in breast cancer. Previously untreated breast carcinoma samples (584) were snap frozen for flow-cytometry. Tumors were classified into three DNA index (DI) categories: i) tumors showing a DI =0.96-1.15 (diploid and near-diploid); ii) tumors with a DI >or=1.16 (hyperdiploid, tetraploid, multiploid and/or those with more than one diploid population); and iii) tumors with a DI