Abstract P5-02-11: Assessment of tumor proliferation by mitotic activity index, phosphohistone H3 and Ki67 in early stage ER+/Her2- breast cancer

Abstract

Introduction: Determining expression of tumor proliferation by mitotic index or Ki67 expression is one of the strongest prognostic factors in breast cancer, but its reproducibility is not optimal. Recently, phosphohistone H3 (PHH3) was proposed as a novel marker specific for mitosis. For the present study, we hypothesized that counting PHH3 positive cells would be more reproducible than mitoses counting in HE 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-02-11.