Dose dense versus 3 weekly AC during neoadjuvant chemoimmunotherapy for triple negative breast cancer

Neoadjuvant pembrolizumab plus chemotherapy (P + CT) has emerged as a standard of care for stage II-III triple-negative breast cancer (TNBC). However, the best anthracycline-cyclophosphamide (AC) schedule remains to be determined. While the KEYNOTE-522 regimen employs AC every 3 weeks (q3w AC), previous studies have shown overall survival benefits of dose-dense regimens for early-stage breast cancer. The Neo-Real study (GBECAM-0123) is a real-world data effort evaluating patients with TNBC treated with neoadjuvant P + CT in ten cancer centers since July 2020. The objective of this analysis was to evaluate the effectiveness and safety of dose-dense AC (ddAC) versus q3w AC. Among 333 patients included until November 2023, 311 completed neoadjuvant therapy and 279 underwent surgery with pathology reports available; ddAC was used in 58.2% and q3w AC in 41.8% of the cases. Most patients (69.1%) had stage II TNBC. A pCR was observed in 65.4% with ddAC and 58.7% with q3w AC (P = 0.260), while RCB 0-1 occurred in 82.4% and 73.5%, respectively (P = 0.115). Patients with stage III disease had a numerically higher pCR with ddAC (59% vs 40%, P = 0.155), while pCR rates were similar regardless of AC regimen in stage II disease (66.6% vs 64.5%; P = 0.760). While no significant disparities in drug discontinuation was noted, ddAC showed a trend towards higher rates of grade ≥3 AE (40.5% vs. 30.7%, P = 0.092). The Neo-Real study could not rule out a difference between ddAC and q3w AC during neoadjuvant P + CT. The observation of a potentially higher pCR with ddAC in stage III disease warrants further investigation.