After adjusting for these variables, we observed that the hazard of breast cancer-specific deaths was significantly reduced in HR−/HER2+ IBC patients (HR: 0.442; 95% CI: 0.216–0.902; P = 0.025) and significantly increased in HR−/HER2- IBC patients (HR: 1.738; 95% CI: 1.192–2.534; P = 0.004) as compared to T4-non-IBC patients. This evidence concerns the gene ERBB2 and breast carcinoma.