Case series of different onset of skin metastasis according to the breast cancer subtypes

We report on five cases of skin metastasis according to the breast cancer (BC) subtype. Two cases of HER2 positive BC showed only skin metastasis after immediate postoperative period and rapid clinical response to targeted therapy. Another two cases of triple negative BC showed thyroid and lung metastasis in addition to skin metastasis, and their response of cytotoxic chemotherapy was not definite. The other hormone positive BC showed skin metastasis only, with a longer, slower, less progressive pattern than other subtypes. Most cases of skin metastasis were detected at terminal stage of malignancy and were considered to have a limited survival period. However, some BC patients can survive longer if the targeted agents are effective. Therefore, physicians should provide detailed follow up of BC after curative treatment and understand the metastatic pattern of BC according to the subtype.