Short-term anastrozole therapy reduces Ki-67 and progesterone receptor expression in invasive breast cancer: a prospective, placebo-controlled, double-blind trial.
Author(s): Mattar A, Logullo AF, Facina G, Nonogaki S, Soares FA, Gebrim LH
Affiliation(s): Department of Gynecology, Federal University of Sao Paulo (UNIFESP), Rua Napoleao de Barros, 715 - 7 degrees .andar, CEP 04024-002, Sao Paulo, SP, Brazil. firstname.lastname@example.org
Publication date & source: 2011-05, J Cancer Res Clin Oncol., 137(5):897-905. Epub 2010 Oct 1.
Publication type: Randomized Controlled Trial
PURPOSE: The objective of this study was to compare Ki-67, Bcl-2, Bax, Bak, ER, and PgR expression in postmenopausal women with ER-positive invasive breast cancer (IBC) before and after short-term hormone therapy (HT) with either tamoxifen or anastrozole in order to identify a possible biomarker profile associated with hormone resistance. METHODS: Fifty-eight patients with palpable IBC were assigned to receive neoadjuvant therapy with either anastrozole, placebo, or tamoxifen for 26 days prior to surgery. Tissue microarray blocks were constructed from pre- and post-treatment biopsy samples and used for immunohistochemical analysis. Biomarker (Ki-67, Bcl-2, Bax, Bak, ER, and PgR) levels were assessed semiquantitatively using the Allred score. A statistical analysis was performed using general estimating equations (GEE) and analysis of variance (ANOVA) with a significance level of 0.05. RESULTS: There was a significant reduction in PgR scores from baseline (mean, 4.22) to post-treatment (mean, 1.94) in the anastrozole group, but only a non-significant trend toward an increase in PgR scores was found in the tamoxifen group. There was a significant reduction in Ki-67 scores from baseline (mean, 3.61) to post-treatment (mean, 2.56) in the anastrozole group (P = 0.01), but only a non-significant trend toward a reduction in Ki-67 scores was found in the tamoxifen group. CONCLUSIONS: There was a significant reduction in PgR and Ki-67 expression in the group treated with anastrozole. In the present study, the short-term HT was not associated with changes in apoptosis-related protein levels, regardless the type of drug used.