Kenta Yagi

With advancements in multidisciplinary treatments such as chemotherapy and radiation therapy, there have been an increasing number of recent reports regarding surgical interventions for unresectable pancreatic ductal adenocarcinoma with metastasis (UR-M PDAC), known as “conversion surgery”. Olaparib, which is one of the treatment options, has been approved as a maintenance treatment in patients with UR-M PDAC and germline BRCA mutations who achieve disease control after a platinum-based regimen such as modified FOLFIRINOX (mFFX). A 49-year-old male patient was diagnosed with PDAC in the pancreatic body-tail. The 1st staging laparoscopy (SL) revealed hepatic metastases in both lobes and positive peritoneal lavage cytology. A germline BRCA2 mutation was considered, and mFFX was introduced and continued for 8 courses, followed by 8 months of olaparib. The initially elevated levels of duke pancreatic monoclonal antigen type 2 and carcinoembryonic antigen subsequently returned to normal, and CT revealed more than 60% shrinkage of the primary tumor. The 2nd SL revealed the disappearance of multiple hepatic metastases and negative conversion of peritoneal lavage cytology, so we performed chemoradiotherapy with olaparib to ensure an antitumor effect and surgical margin negativity, followed by distal pancreatectomy with celiac axis resection. Histopathological findings revealed R0 resection and a pathological complete response (pCR). Adjuvant olaparib treatment was administered for 10 months starting 2 months after surgery, and the patient has remained alive without recurrence for 2 years after surgery. We report the very rare case of a patient with BRCA-positive PDAC with multiple liver metastases who underwent conversion surgery after treatment with mFFX and olaparib, achieved a pCR, and has remained recurrence-free for 2 years.