In a real-world study examining neoadjuvant chemotherapy for human epidermal growth factor receptor 2-positive (HER2+) breast cancer, researchers have identified key predictors of treatment response and long-term survival, providing critical insights for oncologists managing this aggressive disease.
The retrospective analysis evaluated 1,004 patients with nonmetastatic HER2+ breast cancer treated between 2014 and 2018, focusing on factors that influenced pathologic complete response (pCR), event-free survival (EFS), and overall survival (OS). With limited access to HER2-targeted therapies in the study setting, the research highlights the ongoing global disparities in cancer care.
The median patient age was 47, with over half presenting with large tumors (53.1% with T3/T4 staging) and advanced nodal involvement (46.4% with N2/N3 status). While trastuzumab, a HER2-targeted therapy, was administered to 52.6% of patients before surgery, the study found a significant survival benefit for those who received it either in the neoadjuvant or postoperative setting.
A key finding was that achieving a pCR, complete eradication of invasive cancer in the breast and lymph nodes after treatment—dramatically improved outcomes. The 5-year EFS rate for patients who reached pCR was 86.1%, compared to 57% for those who did not (P < .001). Overall, the 5-year EFS for the entire cohort stood at 63.5%. Multivariable analysis revealed that smaller tumor size, higher tumor grade, hormone receptor-negative status, and the use of neoadjuvant HER2-targeted therapy significantly increased the likelihood of achieving pCR. Furthermore, smaller tumors, less nodal involvement, reaching pCR, and receiving trastuzumab were all associated with improved EFS and OS. These findings reinforce the importance of early diagnosis and equitable access to HER2-targeted treatments, particularly trastuzumab, in improving breast cancer outcomes. The study emphasizes that addressing barriers to advanced therapies remains essential for optimizing survival rates in HER2+ breast cancer patients worldwide. Reference: Joshi A et al. Retrospective Study to Determine Factors Influencing Outcome in Patients With Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer Receiving Neoadjuvant Chemotherapy. JCO Glob Oncol. 2025;11:e2400365.
