Superior Long-Term Outcomes Linked to Axillary Pathologic Complete Response After Chemotherapy for Breast Cancer
In an analysis of experience at MD Anderson Cancer Center reported in JAMA Oncology, Mougalian et al found that 10-year overall and relapse-free survival rates in patients with stage II or III breast cancer and axillary metastases receiving primary systemic chemotherapy were higher in those with vs without axillary pathologic complete response. Patients receiving HER2-targeted treatment for HER2-positive disease had a high axillary pathologic complete response rate.
Study Details
The study included data from all 1,600 women (median age at diagnosis = 49 years) who were diagnosed with stage II or III breast cancer with cytologically confirmed axillary metastases and treated with primary systemic chemotherapy between 1989 and 2007. Among these women, 454 (28%) achieved axillary pathologic complete response. These patients were more likely to have HER2-positive and triple-negative disease (P < .001), pathologic complete response in the breast (P < .001), high-grade tumors (P < .001), and lower clinical and pathologic T stage (P = .002).
Pathologic Complete Response vs Residual Disease
For patients with axillary pathologic complete response vs residual disease, 10-year overall survival was 84% vs 57% (P < .001), and 10-year relapse-free survival was 79% vs 50% (P < .001). Among patients with axillary pathologic complete response, 10-year overall survival was 90% for those with breast pathologic complete response vs 72% for those with residual breast disease (P < .001). Among patients with residual axillary disease, 10-year overall survival was 66% for those with breast pathologic complete response vs 56% for those without breast pathologic complete response (P = .02).
Outcomes With HER2-Targeted Therapy
Among 149 patients receiving HER2-targeted therapy for HER2-positive disease, 67% achieved axillary pathologic complete response. Among patients with axillary pathologic complete response vs residual disease, 10-year overall survival was 92% vs 57% (P = .003), and 10-year relapse-free survival was 89% vs 44% (P < .001).
The investigators concluded: “Axillary pathologic complete response was associated with improved 10-year [overall survival] and [relapse-free survival]. Patients with axillary and breast pathologic complete response after [primary systemic chemotherapy] had superior long-term survival outcomes. Patients undergoing HER2-targeted therapy for HER2-positive disease had high rates of axillary pathologic complete response, and those with axillary pathologic complete response had excellent 10-year [overall survival].”
The study was supported by the National Cancer Institute.
Vicente Valero, MD, of the University of Texas MD Anderson Cancer Center, is the corresponding author of the JAMA Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
