Luminal-like HER2-negative stage IA breast cancer: a multicenter retrospective study on long-term outcome with propensity score analysis

// Carmine De Angelis 1 , Massimo Di Maio 2 , Anna Crispo 3 , Mario Giuliano 1, 4 , Francesco Schettini 4 , Marta Bonotto 5 , Lorenzo Gerratana 6 , Donatella Iacono 5 , Marika Cinausero 6 , Ferdinando Riccardi 7 , Giuseppe Ciancia 8 , Michelino De Laurentiis 9 , Fabio Puglisi 6, 10 , Sabino De Placido 4 and Grazia Arpino 4 1 Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas 77030, USA 2 Oncology Department, University of Turin, 10043 Orbassano, Italy 3 Epidemiology Department, ‘Fondazione G. Pascale’ Istituto Nazionale Tumori, 80131 Naples, Italy 4 Clinical Medicine and Surgery Department, University of Naples Federico II, 80131 Naples, Italy 5 Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy 6 Department of Medicine (DAME), University of Udine, 33100 Udine, Italy 7 Medical Oncology Unit, Azienda Ospedaliera di Rilievo Nazionale A. Cardarelli, 80131 Naples, Italy 8 Advanced Biomedical Sciences Department, University of Naples Federico II, 80131 Naples, Italy 9 Breast Unit, ‘Fondazione G. Pascale’ Istituto Nazionale Tumori, 80131 Naples, Italy 10 Department of Clinical Oncology, CRO Aviano National Cancer Institute, 33081 Aviano, Italy Correspondence to: Grazia Arpino, email: grazia.arpino@unina.it Keywords: breast cancer; luminal-like; chemotherapy; hormone therapy; propensity score Received: July 22, 2017     Accepted: October 28, 2017     Published: November 24, 2017 ABSTRACT The benefit of adding chemotherapy (CT) to adjuvant hormone therapy (HT) in stage IA luminal-like HER2-negative breast cancer (BC) is unclear. We retrospectively evaluated predictive factors and clinical outcome of 1,222 patients from 4 oncologic centers. Three hundred and eighty patients received CT and HT (CT-cohort) and 842 received HT alone (HT-cohort). Disease-free survival (DFS) and overall survival (OS) were evaluated with univariate and multivariate analyses. We also applied the propensity score methodology. Compared with the HT-cohort, patients in the CT-cohort were more likely to be younger, have larger tumors of a higher histological grade that were Ki67-positive, and lower estrogen and progesterone receptor expression. At univariate analysis, a higher histological grade and Ki67 were significantly associated to a lower DFS. At multivariable analysis, only histological grade was predictive of DFS. The CT-cohort had a worse outcome than the HT-cohort in terms of DFS and OS, but differences disappeared when matched according to propensity score. In summary, patients with stage IA luminal-like BC had an excellent prognosis, however relapse and mortality were higher in the CT-cohort than in the HT-cohort. Longer use of adjuvant HT or other therapeutic strategies may be needed to improve outcome.