Long-term survival with multidisciplinary treatment including local and systemic treatment for germline BRCA2-positive pancreatic acinar cell carcinoma.

A 59-year-old man was referred with a huge pancreatic mass accompanied by abdominal pain. CT and MRI revealed a 10 cm mass in the pancreatic tail with a well-defined border and internal heterogeneity, and pancreatic acinar cell carcinoma (PACC) and neuroendocrine tumor were considered differential diagnoses. Distal pancreatectomy was performed, and pathological diagnosis was PACC (pT3N0M0; pStage IIA). Tegafur/gimeracil/oteracil (S-1) was administered as adjuvant therapy, however, liver metastasis recurred 3 years after surgery. Modified FOLFIRINOX (FFX) was administered for 1 year, and the metastasis was limited to a solitary lesion on the surface of the liver. Laparoscopic partial hepatectomy was performed. S-1 was administered again, and imaging follow-up was performed. However, liver and lymph node metastases recurred 4 years later (8 years after the initial surgery). FFX was administered for six months, and RECIST PR was achieved. However, continuation of FFX was difficult due to chemotherapy-induced peripheral neuropathy. Olaparib maintenance therapy was selected for germline BRCA2 mutation positive. The liver metastases disappeared, and the therapeutic effect was maintained for one year without any noticeable adverse events. More than 9 years after the initial surgery, the patient is continuing treatment with good performance status.