Clinicopathologic Characteristics and Treatment Outcomes of Triple-Negative Breast Cancer at a Latin American...

Introduction Triple-negative breast cancer (TNBC) lacks estrogen, progesterone, and HER2 receptors, represents a biologically aggressive subtype, and is frequently diagnosed at advanced stages. Regional data on its presentation and outcomes remain limited in Latin America. We evaluated the clinicopathologic features, treatment patterns, and survival of women with TNBC managed at a tertiary referral center. Methods A retrospective descriptive study was conducted of adult patients with pathologically confirmed TNBC who initiated and completed treatment at San Ignacio University Hospital, Bogotá, between August 2017 and June 2023. We reviewed medical records for demographic, tumor, and treatment variables, and we assessed patient responses to neoadjuvant chemotherapy (NAC) with the residual cancer burden (RCB) system. We used the Kaplan-Meier method to generate recurrence-free survival curves and compared survival in the subjects with and without pathological complete response. Results Of 1,083 breast cancer cases, 125 (11.5 %) were identified as TNBC. Most patients presented with stage II-III disease (104/125, 83.2 %) and node positivity (68/125, 54.4 %). NAC was administered to 90/125 women (72%); anthracycline-/taxane-based regimens predominated. Pathologic complete response after NAC occurred in 25/88 cases (28.4%). Forty-six patients had breast-conserving surgery (39.7%), whereas 70 patients (60.3%) underwent mastectomy. The estimated three-year recurrence/progression-free survival (PFS) was 79.4% [95% confidence interval (CI): 71.5%-88.2%]. The estimated three-year overall survival is 74.4% (95% CI: 66%-83.9%). Limited access to germline testing, advanced molecular profiling, and newer systemic agents was evident. Conclusions Within this Latin-American center, TNBC was infrequent yet predominantly diagnosed at advanced stages and carried substantial risks of relapse and death. Earlier detection, broader availability of genetic and molecular testing, and equitable access to emerging targeted and immune-based therapies are essential to improve outcomes in this high-risk population.