Pinto et al. compared the prognosticvalue prognosticvalue of the flow cytometric S-phase fraction and Ki-67 index on230 breast cancer lesions. The results showed S-phase fraction tobe a better prognosticator than Ki-67 index [17]. Similar resultshave been reported for patients with gastric cancer [18]. Thus, flowcytometry metrics are an important predictor of tumour aggres-siveness.