Meta-Analysis Indicates Benefit of Adjuvant Trastuzumab in Early HER2-Positive Breast Cancer With Small Tumors
In a meta-analysis reported in the Journal of Clinical Oncology, O’Sullivan et al found that adjuvant trastuzumab (Herceptin) was associated with a significant disease-free and overall survival benefit among patients with early HER2-positive hormone receptor–positive and hormone receptor–negative disease and tumors ≤ 2 cm, with the magnitude of benefit being smaller in patients with hormone receptor–positive disease and, at most, one positive lymph node.
The meta-analysis included data from five adjuvant trastuzumab trials. As noted by the authors, almost all patients included in the meta-analysis had T1c disease and, thus, constituted a highly selected subgroup.
Disease-Free and Overall Survival
Median follow-up was 8 years. Among 2,263 patients with hormone receptor–positive disease, 8-year cumulative incidence rates for trastuzumab vs no trastuzumab were 17.3% vs 24.3% (P < .001) for disease-free survival events and 7.8% vs 11.6% (P = .005) for death. The rates among the 1,092 hormone receptor–positive patients who have, at most, one positive lymph node were 12.7% vs 19.4% (P = .005) and 5.3% vs 7.4% (P =.12).
Among 1,957 patients with hormone receptor–negative disease, 8-year cumulative incidence rates were 24.0% vs 33.4% (P < .001) for disease-free survival events and 12.4% vs 21.2% (P < .001) for death. Among the 1,040 hormone receptor–negative patients with no more than one positive lymph node, rates were 20.4% vs 26.3% (P = .05) and 8.2% vs 12.2% (P = .084).
The investigators concluded: “Women with HER2-positive tumors ≤ 2 cm in the randomized trastuzumab trials derived substantial [disease-free survival] and [overall survival] benefit from adjuvant trastuzumab. Trastuzumab-treated patients with [hormone receptor–]positive disease and ≤ one positive lymph node may be candidates for trials assessing less aggressive treatment approaches.”
Ciara C. O’Sullivan, MD, of the National Cancer Institute, is the corresponding author for the Journal of Clinical Oncology article.
For full disclosures of the study authors, visit jco.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®.
