The impact of progesterone receptor expression on prognosis of patients with rapidly proliferating, hormone receptor-positive early breast cancer: a post hoc analysis of the IBIS 3 trial. (February 2020)

• Record Type: Journal Article
• Authors: Bravaccini, Sara; Bronte, Giuseppe; Scarpi, Emanuela; Ravaioli, Sara; Maltoni, Roberta; Mangia, Anita; Tumedei, Maria Maddalena; Puccetti, Maurizio; Serra, Patrizia; Gianni, Lorenzo; Amaducci, Laura; Biglia, Nicoletta; Bounous, Valentina; Paradiso, Angelo Virgilio; Silvestrini, Rosella; Amadori, Dino; Rocca, Andrea
• Is Part Of: Therapeutic advances in medical oncology. Volume 12(2020)
• Publication Date: 2020-02
• Subjects: hormone receptor-positive -- immunohistochemistry -- progesterone receptor -- prognosis -- rapidly proliferating breast cancer; Oncology -- Periodicals; Cancer -- Treatment -- Periodicals; 616.994005
• DOI: 10.1177/1758835919888999
• Languages: English
• ISSNs: 1758-8340

Abstract

Background: In the Italian Breast Cancer Intergroup Studies (IBIS) 3 phase III trial, we compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF) alone to sequential epirubicin/CMF regimens in patients with rapidly proliferating early breast cancer (RPEBC). We performed a post hoc analysis in the subgroup of patients with hormone-receptor-positive RPEBC on the prognostic role of progesterone receptor (PgR) status. Methods: RPEBC was defined by thymidine labeling index (TLI) >3% or grade 3 or S-phase >10% or Ki67 >20%. We analyzed 466 patients with hormone-receptor-positive RPEBC receiving sequential epirubicin/CMF regimens followed by tamoxifen, and for whom the status of ER and PgR was available. Results: Considering both cut-off values of 10% and 20%, PgR expression was significantly associated with age, menopausal status, and ER expression; HER2 status was associated with PgR status only at a cutoff value of 20% PgR. Upon univariate analysis, tumor size, nodal status, and PgR were significantly associated with disease-free survival (DFS) and overall survival (OS), while age class and local treatment type were associated only with DFS. Patients with PgR <20% showed lower 5- and 10-year DFS [hazard ratio (HR) = 1.48; 95%CI: 1.01–2.18; p = 0.044] and OS (HR = 1.85; 95%CI: 1.08–3.19, p = 0.025) rates compared with patients with PgR ⩾20%. Upon multivariate analysis, only tumor size, nodal status, and PgR were independent prognostic factors. Conclusions: Our results highlight the independent prognostic relevance of PgR expression in patients with hormone-receptor-positive RPEBC treated with adjuvant chemotherapy and endocrine therapy, where the definition of prognostic subgroups is still a major need.