ERBB2 and ductal breast carcinoma in situ: There are some additional real-world supporting data; in the small number of cases that were upstaged in the study of Grimm et al., of the 81 patients eligible for the COMET trial, only 1 low-grade DCIS was upstaged, to a stage IA invasive no special type carcinoma (T1aN0M0) that was node negative and HER2 negative [31].