Pathologic complete response following FOLFIRINOX and olaparib treatment for hepatic metastasized pancreatic ductal adenocarcinoma with a germline BRCA mutation.

A 47-year-old female who was previously treated for BRCA1 germline mutant breast cancer presented with increasing back pain. Radiological and pathological investigations led to the diagnosis of pancreatic ductal adenocarcinoma with multiple hepatic metastases. Serum carbohydrate antigen 19-9 levels were highly elevated at 14,784 U/mL (normal, < 37 U/mL). After nine cycles of FOLFIRINOX treatment, radiological findings revealed remarkable shrinkage of the primary pancreatic tumor, disappearance of hepatic metastases, and normalized levels of carbohydrate antigen 19-9 levels. Because of increased neuropathy following FOLFIRINOX treatment, the patient was switched to maintenance olaparib treatment. Ten months later, her radiological response and normalized carbohydrate antigen 19-9 levels were stable. After staging laparoscopy, the patient underwent laparoscopic distal pancreatectomy as a conversion surgery. Histopathological examination revealed no signs of residual adenocarcinoma in the resected pancreatic specimens, which was diagnosed as a pathological complete response. The patient recovered without complications. Adjuvant olaparib treatment was administered with no signs of recurrence at 7 months after surgery. In conclusion, a pathologic complete response after FOLFIRINOX and olaparib maintenance treatment in hepatic metastasized pancreatic ductal adenocarcinoma is extremely rare. These bridging treatments may contribute to increased surgical resection rates and improved survival rates.