ERBB2 and cancer: The median estimated cancer size was 2.0 mm (IQR 1.0–4.7) for luminal cancers, 0.6 mm (IQR 0.3–2.1) for HER2-enriched cancers, and 0.3 mm (IQR 0.1–1.3) for triple-negative cancers, p < 0.001.