MKI67 and neoplasm: Compared to responders in the SWEET study in total, non-responders (n = 1448) were significantly older (53.2 years at diagnosis), had lower Ki67 values (mean 27 versus 31), and a larger proportion was HER-2 negative (85% versus 81%), while there were no differences in tumor size, nodal status, hormone receptor status, or type of surgery.