Abstract
BACKGROUND: Guidelines recommend neoadjuvant systemic therapy (NST) as the preferred treatment approach for stage II-III triple-negative breast cancer (TNBC), an aggressive form of breast cancer (BC) that lacks specific therapeutic targets. This study primarily aimed to assess the NST adoption among stage II-III TNBC patients in Greece under real-world conditions during the pre-immunotherapy era. METHODS: This multicenter, observational, retrospective chart review included 230 female patients (≥18 years) with early-stage or locally advanced TNBC across 10 public and private BC reference centers over 6.5 years. Data included demographics and clinical characteristics at diagnosis, treatment details, clinical outcomes, and survival status. Descriptive statistics followed by uni/multivariate analyses were performed. Survival outcomes were assessed using survival analysis methods. RESULTS: Women with stage II (67.4%) or stage III (32.6%) TNBC were included, with a median age of 53.1 years (range 23.9-84.1). Patients received NST [113 (49.1%)] and non-NST [117 (50.9%)]. NST utilization was significantly associated with larger tumor size and BRCA1/2 testing and status. Overall, 43.9% underwent BRCA1/2 testing, and 32.7% of those were positive for a BRCA1/2 mutation. More than half of the patients (n = 61) achieved pathological complete response (pCR) following NST. Event rates were lower with NST (16.8%) versus without (24.8%). Utilization increased over time, peaking at 63.5% in 2020-2022. CONCLUSIONS: NST use showed moderate uptake with notable practice variations, emphasizing the need for multidisciplinary strategies to improve guideline adherence. Over half achieved pCR post-NST, setting a benchmark for TNBC care. Ongoing real-world monitoring is vital to guide long-term outcomes.