Factors, Predicting Failure of Adjuvant Hormonotherapy of Breast Carcinoma. A Study in Tamoxifen Treated Patients.

Background: The latest clinical trials indicate better performance of aromatase inhibitors, compared to tamoxifen, in adjuvant hormonotherapy of breast carcinoma. The identification of molecular markers, predicting resistance to tamoxifen, could help to identify patients, which are most likely to benefit from aromatase inhibitors in up-front adjuvant hormonotherapy.Material and methods: Tissue microarrays were constructed from archival paraffin blocks of primary tumors of 179 patients with estrogen receptor positive operable breast carcinoma in stage I-III, subsequently treated with tamoxifen for five years or until relapse, with at least 7 years follow up available. The amplifications of Her-2 and cyclin D1 genes were evaluated by fluorescence in-situ hybridization. The level of progesterone receptor (PR) and Ki67 were estimated by immunohistochemistry.Results: 54 of above patients recurred during follow up. In univariate analysis of disease free survival, the presence of more than three nodal metastases (RR=4,5 p Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6031.