Helfgott R, et al. - Researchers included all patients with breast cancer, a preoperative axillary ultrasound, and a complete surgical axillary staging for this retrospective single center analysis assessing the impact of biological subtypes on axillary staging with ultrasound (AUS). Studying 583 women, they identified that AUS had sensitivity, specificity, positive and negative predictive value of 39%, 96%, 91% and 83%, respectively. While Luminal A and B patients had significantly lower sensitivity (25.0%; 39.8%) vs non-Luminal breast cancer patients (TN 68.8%; HER2+ 71.4%), no significant differences between the groups were noted regarding specificity, PPV and NPV. These findings suggest that biological subtypes of breast cancer show significant differences only regarding sensitivity of AUS, as lower sensitivity was seen in Luminal patients. While the excellent PPV led to a low overtreatment rate using AUS for clinical decision making, they noted a poor sensitivity overall, similar to results seen with other studies.