Previous studies have identified several risk factors associated with internal mammary lymph node metastasis, including larger tumor size [19,20], advanced axillary lymph node stage [19,21], medial or central tumor location [[20], [21], [22]], younger age [19], and certain molecular subtypes such as HER-2 enriched breast cancer [20,23,24]. This evidence concerns the gene ERBB2 and neoplasm.