A case of pathological complete response after chemotherapy by S-1 and gemcitabine for a pancreatic cancer with para-aortic lymph node metastasis

Abstract

A 67-year-old man with a pancreatic tumor was referred to our hospital on September 2013. The tumor was diagnosed as pancreatic tail cancer invading the splenic artery and vein with para-aortic lymph node metastasis (cStage IVb). After 4 courses of chemotherapy (S-1+gemcitabine), the size of the pancreatic tumor decreased from 21mm to 10mm on CT. Furthermore, CA19-9 level decreased from 67.4U/ml to 9.0U/ml and abnormal accumulation of FDG on FDG-PET in the pancreatic tumor and the para-aortic lymph node disappeared (the values of SUVmax before chemotherapy were 5.3 and 3.7, respectively). Re-evaluation after chemotherapy was cStage IVa pancreatic cancer without lymph node metastasis and curative resection was planned. Distal pancreatectomy with D2 lymph node dissection was performed. At the beginning of the surgery, sampling of the para-aortic lymph node was performed and frozen-section examination revealed no metastatic cancer cells. Histopathological examination of the resected specimens revealed no residual cancer cells in the pancreas and the 34 dissected lymph nodes including para-aortic node (pathological complete response).