The characteristics of pancreatic neck cancer.

Abstract

337 Background: Pancreatic neck cancer occurs in the small region surrounded by the common hepatic artery (CHA), gastroduodenal artery (GDA), and portal vein (PV). The specific clinicopathological characteristics of pancreatic neck cancer remain unclear. This study aimed to identify specific biological behaviors of pancreatic neck cancer for the improvement of treatment outcomes. Methods: This study was a retrospective cohort study and comparative outcomes design. In 63 (19.4%) of 325 consecutive pancreatic cancer patients who underwent surgery, the tumor was located in the pancreatic neck. Clinicopathological characteristics and prognostic factors specific to pancreatic neck cancer were analyzed by comparison to those of pancreatic head or body/tail cancers. Results: The rates of radiographic and pathological PV and/or superior mesenteric vein (PV/SMV) invasion were higher in patients with pancreatic neck cancer (radiographic: 84.1%, pathological: 36.5%) than those with pancreatic head and body/tail cancers (radiographic, head: 67.3%, body/tail: 25.0%, pathological, head: 26.0%, body/tail: 6.3%). The most frequent lymph node metastasis was found in the region along the CHA in pancreatic neck cancer, and the spots most likely to show a positive surgical margin were the dissected surface of the PV and the root of the GDA and/or CHA. For pancreatic neck cancer patients, five independent poor prognostic factors were found: pathological PV/SMV invasion (P= 0.005), moderately or poorly differentiation (P= 0.001), positive lymph node ratio ≥ 0.1 (P< 0.001), surgical margin length ≤ 1 mm (P= 0.018), and no completion of planned postoperative adjuvant therapy (P< 0.001). Conclusions: Pancreatic neck cancer showed specific clinicopathological characteristics and prognostic factors after resection. Patients with these risk factors might need multimodality treatment strategies, including neoadjuvant therapy, in order to prolong the survival, although further studies will be necessary to confirm our findings.