Response of extensive breast cancer skin metastases to rechallenge with trastuzumab together with low-dose chemotherapy and insulin.

Introduction: Cutaneous metastasis occurs in about 29% of breast cancer patients and has a deep impact on patient quality of life.

Methods: A 60-year-old woman with cutaneous metastases from heavily pretreated HER2-positive breast cancer received CMFVP (oral cyclophosphamide 100 mg daily; oral prednisone 12.5 mg daily for 2 weeks, then 7.5 mg daily; intravenous weekly methotrexate 25 mg/m2, 5-5-fluorouracil 400 mg/m2 and vincristine 0.5 mg) with weekly trastuzumab and subcutaneous insulin until disease progression.

Results: From March 2009 to November 2009 the patient was treated with the described regimen. At the best response, we observed the disappearance of some lesions and cessation of bleeding and thoracic pain. Time to progression was 8 months.

Conclusions: Our patient had clinical benefit from reintroduction of trastuzumab, low-dose chemotherapy and insulin. The explanation of this prolonged response is only speculative and requires further clinical confirmation in the treatment strategy of HER2-positive breast cancer.