ERBB2 and cancer: A subgroup analysis was conducted for patients with triple-negative breast cancer (TNBC), HER2+ cancer, ER+, or ‘favorable’ disease (i.e., that likely to be curable with RT [ER+, HER2–, cT1-2, cN0, age >60 years]) to assess whether RT chemotherapy, or hormone therapy was associated with differences in OS in these subgroups (Fig. 2).