[A Case of Borderline Resectable Pancreatic Adenosquamous Carcinoma Achieving Pathological Complete Response].

The patient was a 66-year-old man presenting with epigastric pain and jaundice. PET-CT demonstrated limited-accumulation on the tumor at the head of the pancreas, diagnosed as borderline resectable adenosquamous carcinoma. The patient was treated with preoperative chemoradiation therapy with 2 courses of gemcitabine followed by administration of S-1 and gemcitabine for 13 months, which reduced the tumor size. After preoperative therapy, pancreaticoduodenectomy was performed. Histopathological examination revealed that no viable tumor cells were detected in the pancreas or lymph nodes, and the patient had achieved a pathological complete response. Postoperative adjuvant chemotherapy was not performed, and the patient is still alive without recurrence for 66 months after surgery.