Pancreatic neck cancer has specific and oncologic characteristics regarding portal vein invasion and lymph node metastasis

Abstract

Pancreatic cancer originating in the neck of the gland occurs in the small region surrounded by the common hepatic artery (CHA), gastroduodenal artery (GDA), and portal vein (PV). The specific clinicopathologic characteristics of pancreatic neck cancer remain unclear. Our aim was to identify specific biologic behaviors of pancreatic neck cancer for the improvement of treatment outcomes. This study was a retrospective cohort study with a comparative outcomes design. In 63 of 325 consecutive patients (19.4%) with pancreatic cancer who underwent operation, the tumor was located in the pancreatic neck. Clinicopathologic characteristics and prognostic factors specific to pancreatic neck cancer were analyzed by comparison with those of pancreatic head or body/tail cancers. The rates of radiographic and pathologic PV and/or superior mesenteric vein (PV/SMV) invasion were greater in patients with pancreatic neck cancer (radiographic, 84%; pathologic, 37%) than those with pancreatic head and body/tail cancers (radiographic: 67% head, 25% body/tail; pathologic: 26% head, 6% body/tail). The most frequent lymph node (LN) metastases were found in the region along the CHA in pancreatic neck cancer, and the areas 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, 5 independent poor prognostic factors were found: pathologic PV/SMV invasion (P=.005), moderately or poorly differentiated tumors (P=.001), positive LN ratio of ≥0.1 (P<.001), distance from surgical margin of ≤1mm(P=.018), and inability to complete the planned postoperative adjuvant therapy (P<.001). Pancreatic neck cancer showed specific clinicopathologic characteristics and prognostic factors after resection.