Clinical characteristics, risk factors, and outcomes in Chilean triple negative breast cancer patients: a real-world study.

Abstract

Latin American (LA) studies on triple-negative breast cancer (TNBC) and their characteristics are scarce. This forces physicians to make clinical decisions based on data obtained from studies that include non-Hispanic patients. Our study sought to obtain local epidemiological data, including risk factors and clinical outcomes from a Chilean BC registry. This was a retrospective population-cohort study that included patients treated at a community hospital (mid-low income) or an academic private center (high income), in the 2010-2021 period. Univariate and multivariate analyses were performed to identify prognostic factors associated with survival. 647 out of 5,806 BC patients (11.1%) were TNBC. These patients were younger (p = 0.0001) and displayed lower rates of screening-detected cases (p = 0.0001) compared to non-TNBC counterparts. Among TNBC patients, lower income (i. e., receiving treatment at a community hospital) was associated with poorer overall survival (HR: 1.53; p = 0.0001) and poorer BC specific survival (HR: 1.29; p = 0.004). Other risk factors showed no significant differences between TNBC and non-TNBC. As expected, 5-year OS was significantly shorter on TNBC versus non-TNBC patients (p = 0.00001). In our multivariate analyses TNBC subtype (HR: 2.30), locally advanced stage (HR: 7.04 for stage III), lower income (HR: 1.64), or non-screening detected BC (HR: 1.32) were associated with poorer OS. To the best of our knowledge, this is the largest LA cohort of TNBC patients. Interestingly, the proportion of TNBC among Chileans was smaller compared to similar studies within LA. As expected, TNBC patients had poorer survival and higher risk for early recurrence versus non-TNBC. Other relevant findings include a higher proportion of premenopausal patients among TNBC. Also, mid/low-income patients that received medical attention at a community hospital displayed lower survival versus private health center counterparts.