Journal: NPJ breast cancer
This population-based study evaluated trends and outcomes of neoadjuvant chemotherapy (NACT) in adults with stage I–III HER2-positive breast cancer who underwent surgery and chemotherapy between 2010–2022 (n=195,023).
Key findings:
- NACT utilization:
– Used in 37.7% of patients overall.
– Increased substantially over time, from 18.6% in 2010 to 63.4% in 2022 (p<0.001), reflecting rapid adoption of neoadjuvant strategies in HER2-positive disease.
- Pathologic complete response (pCR):
– pCR rates improved from 21% in 2010 to 47.6% in 2022 (p<0.001), consistent with more effective systemic regimens and optimization of HER2-directed therapy.
- Racial disparities:
– Black patients were slightly less likely than White patients to receive NACT (adjusted OR 0.96; 95% CI 0.93–0.99).
– Among those receiving NACT, Black patients were also less likely to achieve pCR (adjusted OR 0.86; 95% CI 0.82–0.90).
– These data suggest both treatment access and treatment effectiveness gaps by race.
- Survival impact of pCR:
– Achieving pCR was strongly associated with improved overall survival (adjusted HR for death 0.45; 95% CI 0.42–0.48).
– Three-year overall survival (OS) improved over time for both groups:
– Without pCR: from 91% (2010) to 95% (2019) (p<0.001).
– With pCR: from 97% to 99% over the same period (p=0.002).
Clinical implications:
NACT use and pCR rates have risen markedly in early-stage HER2-positive breast cancer, and pCR remains a robust surrogate for better survival. However, persistent racial disparities in both NACT utilization and pCR achievement highlight an urgent need for interventions to improve equitable access to optimal neoadjuvant care and to investigate underlying systemic and biologic contributors.