Clinical Behavior of Triple Negative Breast Cancer in a Cohort of Latin American Women

Introduction: Breast cancer is a worldwide public health problem. In Colombia, there are 13,000 new cases, having the highest incidence and mortality among cancers. This article describes the clinical behavior of patients with triple negative breast cancer (TNBC) treated at the National Cancer Institute (NCI) in Bogota, Colombia. Methods: A historical cohort and analytical study that included elderly patients diagnosed with TNBC treated at the National Cancer Institute Functional Breast Cancer Unit (NCI-FBCU) was conducted. Results: Of the 1,066 patients registered in the unit from September 1st 2013 to December 31st 2016: 146 (13.7 %) had triple negative tumors. The average age was 57.3 years; 61% of patients had locally advanced tumors. The majority of patients received neoadjuvant chemotherapy as their first treatment (69.1%), and in 41.2% of the cases platinum was added to the chemotherapy regimen. The most common surgery conducted was modified radical mastectomy in 57.8% of cases. The pathological complete response (pCR) (Chevallier 1 and 2) was reached in 22.6% and, in this group of patients, a greater overall survival (OS) was found [hazard ratio (HR) 0.08, 95% CI 0.01-0.63; p = 0.016]. Progression of the disease occurred in 36.5% of cases, being lungs the most frequent location (44.4%). The death incidence rate was 1.21 deaths per 100 patients/month. The median event-free survival (EFS) was 18.2 months. Conclusion: TNBC occurs in Latin American women at advanced clinical stages with aggressive clinical behavior, with lower OS rates, and higher risk of metastasis compared to other molecular subtypes.