In an analysis reported in the Journal of Clinical Oncology, Marion T. van Mackelenbergh, MD, PhD, and colleagues found that patients with early HER2-positive breast cancer who achieved pathologic complete response (pCR) on neoadjuvant chemotherapy plus anti-HER2 treatment had better overall and event-free survival vs those who did not achieve pCR.
The analysis used individual data from 3,710 patients in 11 randomized neoadjuvant trials that enrolled 100 or more patients; had available data on pCR, event-free survival, and overall survival; and a follow-up of ≥ 3 years.
Marion T. van Mackelenbergh, MD, PhD
Median follow-up was 61.2 months. A total of 1,497 patients (40.4%) achieved a pCR.
In patients with pCR, cT status (cT1-2 vs cT3-4; hazard ratio [HR] = 0.67, P = .007) and cN status (cN0 vs cN1; HR = 0.72, P = .039) were independent prognostic factors for event-free survival. Only cT status was significantly prognostic for overall survival (HR = 0.55, P = .011).
In patients without pCR, cT, cN, and hormone receptor–positive vs –negative status were independent prognostic factors for event-free survival (HRs = 0.62, P < .001; 0.66, P <.001; and 0.59, P = .005, respectively) and overall survival (HRs = 0.47, P < .001; 0.75, P = .025; and 0.44, P <. 001, respectively).
Overall hazard ratios for pCR vs no pCR were 0.39 (95% confidence interval [CI] = 0.34–0.46, P < .001) for event-free survival and 0.32 (95% CI = 0.26–0.41, P < .001) for overall survival. Regardless of hormone receptor, cT, and cN status, 5-year event-free survival and overall survival were higher among patients with vs without pCR. For example, among patients with hormone receptor–positive disease, 5-year event free survival was 91.4% vs 84.5% among those with T1-2, N- disease; 87.0% vs 73.2% among those with T3-4, N- disease; 83.6% vs 72.1% among those with T1-2, N+ disease; and 80.4% vs 60.9% among those with T3-4, N+ disease. Corresponding figures for 5-year overall survival were 98.6% vs 96.3%, 92.9% vs 81.8%, 95.1% vs 88.9%, and 94.0% vs 84.9%.
In most subsets according to hormone receptor and pCR status, cT and cN were independent prognostic factors for both event-free survival and overall survival, including in patients with pCR.
The investigators concluded, “These results confirm that patients achieving pCR have far better survival outcomes than patients who do not. The traditional poor prognostic features, namely tumor size and nodal status, remain important even after a pCR.”
Dr. van Mackelenbergh, of Universitaetsklinikum Schleswig-Holstein, Campus Kiel, Kiel, Germany, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.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®.