ERBB2 and breast cancer: Among premenopausal women 50 years or younger, however, a modest benefit was noted among those with an RS of 21 to 25 or 16 to 20 with higher clinical risk.9,10 In 2020, the RxPONDER trial evaluated patients with HR-positive, ERBB2-negative breast cancer with up to 3 positive lymph nodes; no chemotherapy benefit was seen in patients with low to intermediate genomic risk (RS ≤25).