Differential Response of Immunohistochemically Defined Breast Cancer Subtypes to Anthracycline-Based Adjuvant Chemotherapy with or without Paclitaxel

摘要: Background: The aim of the present study was to investigate efficacy adjuvant dose-dense sequential chemotherapy with epirubicin, paclitaxel, and CMF in subgroups patients high-risk operable breast cancer, according tumor subtypes defined by immunohistochemistry (IHC). Materials Methods: Formalin-fixed paraffin-embedded (FFPE) tissue samples from 1,039 participating two phase III trials were centrally assessed micro-arrays IHC for 6 biological markers, that is, estrogen receptor (ER), progesterone (PgR), HER2, Ki67, cytokeratin 5 (CK5), EGFR. majority cases further evaluated HER2 amplification FISH. Patients classified as: luminal A (ER/ PgR-positive, HER2-negative, Ki67 low ); B (ER/PgR-positive, high luminal-HER2 HER2-positive); HER2-enriched (ER-negative, PgR-negative, triple-negative (TNBC) PgRnegative, HER2-negative); basal core phenotype (BCP) (TNBC, CK5-positive and/or EGFR-positive). Results: After a median follow-up time 105.4 months 5-year disease-free survival (DFS) overall (OS) rates 73.1% 86.1%, respectively. Among tumors there significant benefit both DFS OS (log-rank test; p=0.021 p=0.006, respectively) those treated paclitaxel. subtype classification found be predictive prognostic value. Setting as referent category, adjusted factors HR relapse TNBC 1.91 (95% CI: 1.31–2.80, Wald’s p=0.001) death 2.53 1.62– 3.60, p,0.001). Site first differed subtype. Locoregional relapses brain metastases more frequent TNBC, while liver often seen tumors. Conclusions: Triple-negative is adverse value chemotherapy. In pre-trastuzumab era, predicts favorable outcome following paclitaxel-containing treatment.