Publication Abstract

Authors: Oestreicher N, White E, Malone KE, Porter PL

Title: Hormonal factors and breast tumor proliferation: do factors that affect cancer risk also affect tumor growth?

Journal: Breast Cancer Res Treat 85(2):133-42

Date: 2004 May

Abstract: BACKGROUND: Tumor cell proliferation is one of the most significant predictors of prognosis for women with breast cancer. Personal characteristics that affect hormonal exposure have been implicated in breast tumor etiology, and it is possible that they may also influence tumor cell proliferation. We examined the association between hormone-related breast cancer risk factors and breast tumor proliferation, as reflected in two proliferation measures, Ki-67 and mitotic count. METHODS: The study population was 484 women 40 years of age and older, who were members of a managed care organization's breast cancer screening program and were diagnosed with invasive breast cancer between 1988 and 1995. The percent of Ki-67 positive tumor cells averaged over four high powered fields (Ki-67) was log transformed and analyzed in a linear regression model. Mitotic count was dichotomized into high versus low (