Significance of GATA3 Expression in Outcomes of Breast Cancer Patients Who Received Systemic Chemo and/or Hormonal Therapy and Clinicopathological Features of GATA3 Positive Tumors
Maria Surowiecka, Cindy Blair, Dennis Knapp, Linda Varghese, Evin Gulbahce. University of Minnesota, Minneapolis, MN; University of Alabama at Birmingham, Birmingham, AL; VAMC, Minneapolis, MN; Fairview Southdale Hospital, Edina, MN
Background: GATA3 and ER are involved in a positive cross-regulatory loop and are frequently coexpressed in breast cancers. GATA3 expression was shown to be an independent predictor of response neoadjuvant chemotherapy, and overall and disease free survival in some studies, while others showed no difference. We investigated the association of GATA3 expression with clinicopathologic variables and outcome in patients who received systemic chemo and/or hormonal therapy.
Design: Breast cancer tissue microarray blocks from 516 women who received systemic chemo and/or hormonal therapy were used for GATA3 immunohistochemistry. Patients' clinicopathologic findings and outcomes were correlated to GATA3 expression. Nuclear staining ≥1% was considered positive for GATA3, ER, and PR.
Results: 436/516(84.5%) of the cases were GATA3 +. GATA3 + tumors were more likely to be higher stage (p=0.01), and have Grade 1 or 2, ER+, PR + and non-triple negative phenotypes (all p<0.0001). ER -/GATA3 + tumors, compared to ER-/GATA3- tumors, had worse breast cancer survival (BCS) (p=0.02), and trend for worse overall survival (OS) (p=0.05) in univariate analysis. There was no difference in OS and BCS between patients who received chemo and/or hormonal therapy among GATA3 + and – cases.
Conclusions: When positivity is evaluated similar to ER/PR (i.e. ≥1% is +), GATA3 + tumors are correlated with lower grade, ER+, PR +, and non-triple negative phenotypes. Although there was no difference in OS and BCS between GATA3 + and – groups, there was an adverse effect of GATA3 expression among the ER subgroup of patients who received systemic therapy.
Tuesday, March 5, 2013 1:00 PM
Poster Session IV # 60, Tuesday Afternoon