MKI67 and breast cancer: For example, a metanalysis of 12,155 breast cancer patients showed that, in the overall population, Ki-67 expression was associated with decreased overall (HR 1.95, 95% CI: 1.70–2.24; P < 0.001) and disease-free survival (HR 1.93, 95% CI: 1.74–2.14; P < 0.001) (146).