Other factors associated with increased risk of CBC were family history; higher nuclear grade; HR–/ERBB2– subtype; carcinoma in situ (patients with Tis-stage cancer had higher risk of developing CBC than those with invasive cancer with lesions less than 5 cm in diameter); in case of invasive cancer, higher T stage; and no treatment with hormone therapy (eTable 2 in Supplement 1). This evidence concerns the gene ERBB2 and cancer.