Prognostic factors impacting survival in early HER2-positive breast cancer (BC): Results from a 1,142 patients database study.

Abstract

e12561 Background: early systemic therapy has reduced recurrence and mortality from BC, especially among HER2+ subtype. Despite these advances, the difficulty of developing countries in incorporating new treatments, as well as the molecular and phenotypic profiles of HER2+ BC, are associated with the heterogeneity of treatment responses, leading to poor prognosis and outcomes. However, real-world data on prognostic factors for early HER2+ BC patients are scarce, especially in the Brazilian context. Therefore, this study aims to evaluate the influence of prognostic factors on disease-free survival (DFS) and overall survival (OS) in early HER2+ BC patients. Methods: this retrospective study identified early HER2+ BC (stage I to III with positive immunohistochemistry and in-situ hybridization) patients from Pérola Byington’s public hospital database (São Paulo, Brazil) diagnosed between January 2010 to March 2018. Patients were excluded if they were less than 18 years old, participated in clinical trials, presented metastatic disease de novo, concurrent malignancy, or inconsistent data. Multivariate Cox regression was used to evaluate prognostic factors for survival, and OS and DFS were estimated by Kaplan-Meier analyses. Results: of the 1,625 patients identified in the database, 1,142 women were included in the study. Of those, 40% were diagnosed with less than 50 years old. Among the included patients, 40.3% were HR-/HER2+ and 59.7% were HR+/HER2+. In addition, 19.4% of patients were diagnosed at stage I, 42.9% at stage II and 37.7% at stage III. A total of 1033 patients were included in the DFS analysis, with a probability of 71.8% DFS in 5-years. For OS analysis, a probability of 75.4% OS in 5-years was observed for 1139 patients included. The multivariate analysis showed that tumor staging, lymph node involvement and pathological complete response (pCR) were independent prognostic factors for both DFS and OS. Conclusions: the study in the Brazilian cohort corroborates the literature, showing that tumor staging, pCR, and lymph node involvement are key markers for DFS and OS and they should be considered when managing the early HER2+ BC patients. [Table: see text]