Tumor proliferation status was another relevant prognostic factor evaluated in the literature series in small, node-negative, breast cancers (Hanrahan et al. 2007; Colleoni et al. 2004; Railo et al. 2007), resulting a high proliferative index a significant negative prognostic factor; in our casistic, Ki-67 was confirmed to be an independent prognostic factor at multivariate Cox analysis. Here, MKI67 is linked to breast cancer.