In an individual patient-level meta-analysis reported in The Lancet Oncology, Villacampa et al found that the HER2DX assay risk score was prognostic for event-free survival outcomes in patients with early-stage, HER2-positive breast cancer.
Study Details
Systematic review of the literature identified 11 eligible studies with more than 50 patients with stage I to III HER2-positive breast cancer who had data on HER2DX risk scores, clinical information, and event-free survival outcomes. HER2DX risk score was evaluated as a continuous score and as a risk group using preestablished cutoffs (low vs high). The primary outcome measure of the analysis was event-free survival.
Key Findings
A total of 2,518 patients were included in the analysis. In total, 35.4%, 45.0%, and 19.6% of patients had stage I, II, and III disease, respectively. A total of 65.9% had hormone receptor–positive disease.
Among the 2,518 patients, 1,259 (50.0%) had a high HER2DX risk score. Median follow-up was 6.1 years (95% confidence interval [CI] = 6.0–6.3 years). In a multivariable analysis, HER2DX as a continuous variable was independently associated with event-free survival (stratified hazard ratio [HR] per 10-unit increment in risk score = 1.25, 95% CI = 1.14–1.38, P < .0001). Patients in the HER2DX low-risk group had a 6-year event-free survival rate of 93.6% (95% CI = 92.0%–95.2%) vs 82.9% (95% CI = 80.0%–85.5%) for the HER2DX high-risk group, yielding a 10.7% absolute difference (stratified HR = 2.72, 95% CI = 1.97–3.76, P < .0001).
The associations were consistent across subgroups, regardless of tumor stage, nodal stage, pathologic complete response, or hormone receptor status, according to the study authors.
The investigators concluded: “HER2DX provides clinically meaningful prognostic stratification in early-stage HER2-positive breast cancer, beyond standard clinical-pathological variables and pathological response. These results support its use in tailoring treatment intensity and guiding clinical decision making.”
Aleix Prat, MD, of Cancer Institute and Blood Disorders, Hospital Clínic de Barcelona, Barcelona, is the corresponding author of The Lancet Oncology article.
Disclosure: The study was funded by Reveal Genomics. For full disclosures of all study authors, visit thelancet.com.
