Resumen de Characterization of HER2/neu and topoisomerase IIa status by FISH in locally advanced breast cancer
Josep Maria Corominas Torres, Berta Laquente Sáez, Francesc Solé Ristol, Ignacio Tusquets Trias de Bes, Meritxel Bellet Ezquerra, Sergio Serrano Figueras, Marta Salido Galeote, Cristina Corzo Contero, Xavier Fabregat Mayol
Background. HER2/neu encodes a receptor related to breast cancer pathogenesis and topoisomerase IIa is an enzyme involved in response to anthracycline chemotherapy. The aim of this study is to analyse HER2/neu and topoisomerase IIa in a homogenous series of 49 patients with locally-advanced breast cancer (LABC) to determine their status and predictive value with respect to response to treatment.
Material and methods. Paraffin-embedded tissues samples from patients with LABC (prior to their neoadjuvant chemotherapy programme) were analysed using the FISH technique.
Results. HER2 amplification was noted in 29% of cases of which 77% presented amplification in the topoisomerase IIa gene, 15% had deletion and 8% did not show any aberration in topoisomerase IIa status.
Conclusions. These preliminary analyses show a correlation between HER2 amplification and topoisomerase IIa status (92%), and suggest that patients with non-amplified HER2/neu or topoisomerase IIa have better response and have and increase (albeit not statistically significant) in disease-free survival (DFS). However, the limited numbers of patients in the study preclude definitive conclusion regards the value of these genes in predicting patient response to anthracycline-based chemotherapy.
