Pancreatic cancer in the remnant pancreas following primary pancreatic resection

To clarify the clinical features of cancer in the pancreatic remnant. We retrospectively reviewed the clinical and pathological findings of 10 patients who developed remnant pancreatic cancer in our hospital between 2002 and 2012. The KRAS sequences in both the initial pancreatic tumor and remnant pancreatic cancer were examined in two patients. Eight patients underwent a second pancreatectomy for remnant pancreatic cancer (resected group), while two patients were not operated on and underwent chemotherapy (unresected group). The remnant pancreatic cancer developed at the cut end of the pancreas (pancreaticogastrostomy site) in four patients. In the resected group, four patients died 17 months after the emergence of the remnant pancreatic cancer and four patients survived during the median 40.5-month observation period. The median survival of the unresected group after the emergence of the remnant pancreatic cancer was 10 months. The findings of the KRAS sequencing and immunohistological staining of the remnant pancreatic cancer for MUC1 and MUC2 in the two patients were consistent with those of the initial pancreatic tumor in one patient, and not consistent in the other. Our results suggest that both local recurrence and a new primary cancer can develop in the pancreatic remnant, and repeated pancreatectomy can prolong survival.