[A Case of Synchronous Double Cancer including Borderline Resectable Pancreatic Body Cancer and Breast Carcinoma with Osseous/Cartilaginous Differentiation Treated with Neoadjuvant Chemotherapy and Radical Resection].

A 78-year-old woman with a left breast cancer was examined at our institute. Ultrasonography showed 48 mm sized mass at zone C of the left breast, and left axillary lymph node swelling. Pathological examination of core needle biopsy revealed invasive ductal carcinoma and lymph node metastasis. In addition, contrast computed tomography showed 30 mm sized an hypovascular mass at pancreatic body involved the portal vein. Endoscopic ultrasound guided fine needle aspiration biopsy of the pancreas revealed adenocarcinoma. The diagnosis was synchronous double cancer including borderline resectable pancreatic body cancer and left breast cancer, and she received neoadjuvant chemotherapy consisting of gemcitabine and nab-paclitaxel. The effect of neoadjuvant chemotherapy was judged to be stable disease for breast cancer, partial response for pancreatic cancer. Then, she underwent pancreatosplenectomy with portal vein and gastroduodenal artery resection and reconstruction, left mastectomy and axillary lymph node dissection. Pathologic examination of the excised specimen revealed the diagnosis of breast cancer with osseous/cartilaginous differentiation and pancreatic moderately differentiated adenocarcinoma. She was treated with fluorouracil, epirubicin, and cyclophosphamide as adjuvant therapy, and there has been no recurrence.