Ki 67 Diagnostic BioSystems blog

Ki67 is a nuclear marker of cell proliferation, with expression proportional to mitotic count. It can therefore be used as an adverse marker. In breast carcinoma, in conjunction with ER, PR, and Her2, Ki67 is used for evaluation of prognosis. In this setting, the percentage of positive staining in tumor nuclei is scored as <10% (low), 10 – 20% (intermediate) and >20% (high). It has been used to help distinguish benign versus malignant and increasingly used to grade various tumors or dysplasia in gastrointestinal, genitourinary, reproductive tract, pulmonary and breast, etc.. For most of tumors, the Ki67 positive staining percentage is also used to grade tumors and scored as low grade(<3%) , intermediate grade(3-20%), high grade(>20%).