Long-term Complete Response with Lapatinib Plus Capecitabine in a Patient with HER2-Positive Breast Cancer Metastasized to the Pancreas

A 37-year-old woman underwent a total mastectomy and adjuvant chemotherapy for HER2-positive breast cancer (pT1N0M), and then recurred in the right lung followed by the pancreas. Lung lobectomy and pylorus-preserving pancreaticoduodenectomy were performed, and systemic chemotherapies including trastuzumab were sequentially administered. However, metastasis to the pancreatic tail was detected. She underwent image-guided radiation therapy, but this was not effective. Lapatinib plus capecitabine combination was administered as forth-line treatment and the metastatic lesion was disappeared. She is continuing this regimen with a complete response for 48 months until now.