MKI67 and invasive breast carcinoma: In the 344 female dogs with invasive mammary carcinoma, the histological stage was a significant prognostic factor associated with disease-free interval by multivariate analysis (HR = 3.60 for stage IIIB, HR = 2.66 for stage IIIA CMCs compared to stage I; Table 5), with 2 independent covariates (p < 0.0001): the immunophenotype (HR = 1.64 for triple-negative CMCs compared to luminal), and the Ki-67 proliferation index (HR = 1.70 for CMCs with Ki-67 index ≥20% compared to <20%).