Patients with MCT-1 gene overexpression also exhibited lower recurrence-free survival (RFS) in overall breast cancer (p = 1E-16) as well as in TP53 wild type (p = 0.029) (Additional file 1: Figure S1B), lymph node metastasis (p = 0.017) and metastasis-free (p = 0.00096), ER-negative (p = 0.015), HER2-negative (p = 1E-06), TNBC (p = 0.046), luminal-A (p = 5E-08) and luminal-B (p = 2.3E-06) breast cancer than did patients with low MCT-1 levels. Here, ERBB2 is linked to breast cancer.