Background: In the US, triple-negative breast cancer (TNBC) represents about 10–20% of breast cancers. Current information about the clinical and economic burden of early-stage TNBC in elderly patients is lacking. Methods: We used the SEER-Medicare database to identify patients with continuous Medicare Parts A/B enrollment, ≥66 years old, newly diagnosed between 2010 - 2015 (followed until 2016) with stage II-III TNBC, who initiated systemic neoadjuvant and/or adjuvant (including chemotherapy and radiation) therapy. Overall survival (OS) and event-free survival (EFS) from diagnosis were estimated using Kaplan-Meier (KM). Healthcare costs were determined during neoadjuvant and adjuvant periods. Results: Of 1569 patients ( > 99% women), 94 (6%) received neoadjuvant therapy, 1162 (74%) received adjuvant therapy, and 313 (20%) received both (neo/adj; Table). Age and race/ethnicity distributions were comparable in the three cohorts. Primary tumor T stage was T1c/T2 for 43%, 83%, and 58% in neoadjuvant, adjuvant, and neo/adj, respectively, and T3 for 14%, 10%, and 15%, respectively. The most common systemic regimens in both neoadjuvant and adjuvant periods were a taxane +/- anthracycline; 21% and 67% of patients in adjuvant and neo/adj cohorts received radiation therapy after surgery. Most claims were for outpatient treatment; hospitalizations were uncommon. The total mean expenditures per patient per month were US$10,620 and $24,408 during neoadjuvant and adjuvant periods, respectively. Conclusions: This study provides insights into patient characteristics, as well as clinical and economic outcomes for elderly patients with early-stage TNBC, treated from 2010-2016 in the US, highlighting the high monetary burden of TNBC and poor outcomes associated with stage III patients.

(Data cut-off 31Dec2016. NR, not reached.)