Clinical implications of lymphadenectomy for invasive ductal carcinoma of the body or tail of the pancreas

AIM: The appropriate extent of lymphadenectomy for pancreatic cancer of the body/tail has not been standardized worldwide. The present study evaluated the optimal extent of harvesting lymph nodes. METHODS: Patients who underwent distal pancreatectomy for invasive ductal carcinoma of the pancreas between 2007 and 2018 were retrospectively reviewed. Patients were subclassified into three groups depending on the tumor location: pancreatic body (Pb), proximal pancreatic tail (Ptp), and distal pancreatic tail (Ptd). The pancreatic tail was further divided into even sections of Ptp and Ptd. Patterns of lymph node metastasis and the impact of lymph node metastasis on the prognosis were examined. RESULTS: A total of 120 patients were evaluated. Fifty‐eight patients had a tumor in the Pb, 38 in the Ptp, and 24 in the Ptd. No patients with a Ptd tumor had metastasis beyond the peripancreatic and splenic hilar lymph nodes (LN‐PSH). All patients with metastasis to the lymph nodes along the common hepatic artery (LN‐CHA) or along the left lateral superior mesenteric artery (LN‐SMA) also had metastasis to the LN‐PSH. Recurrence after surgery occurred significantly earlier in this population. In a multivariate analysis, metastasis to the LN‐CHA or LN‐SMA (hazard ratio [HR] 3.3; P = .04) was an independent risk factor for overall survival. Furthermore, high levels of preoperative serum CA19‐9 (HR 10.9; P = .013) were a predictive factor for metastasis to the LN‐CHA or LN‐SMA. CONCLUSIONS: Metastasis to the LN‐CHA or LN‐SMA was rare but a significant prognostic factor in patients with pancreatic body/tail cancer.