Survival Outcomes in Metaplastic Versus Triple-Negative Invasive Breast Carcinoma: A Propensity Score-Matched Study

Background and Objectives: Metaplastic breast carcinoma (MBC) is a rare, predominantly triple-negative breast cancer subtype with aggressive clinical behaviour. This study compared the clinicopathological characteristics and survival outcomes of MBC with triple-negative invasive breast carcinoma (TN-IBC) and assessed the prognostic value of the neutrophil-to-lymphocyte ratio (NLR). Materials and Methods: Patients with stage I-III MBC or TN-IBC diagnosed between January 2003 and January 2024 were retrospectively reviewed. Among 35 patients with MBC and 103 with TN-IBC, 1:1 propensity score matching by age and TNM stage generated two groups of 35 patients. Disease-free survival (DFS) and overall survival (OS) were evaluated using Kaplan-Meier estimates and Cox proportional hazards models with robust sandwich variance clustered by matched pair.