Reconsidering the Optimal Regional Lymph Node Station According to Tumor Location for Pancreatic Cancer.

BACKGROUND

A consensus regarding the optimal extent of lymph node dissection for pancreatic cancer has not yet been achieved. The purpose of this study was to evaluate the efficacy of lymph node dissection according to the location for pancreatic cancer.

METHODS

A total of 495 patients diagnosed with invasive ductal carcinoma of the pancreas who had undergone a pancreatectomy between October 2002 and December 2015 were analyzed. The efficacy index (EI) was calculated for each lymph node station via multiplication of the frequency of metastasis to the station and the 5-year survival rate of the patients with metastasis to that station.

RESULTS

For pancreatic head (Ph) tumors, mesocolon lymph nodes had a high EI, although not regional. For pancreatic body (Pb) tumors, peri-Ph lymph nodes had a high EI, although not regional. For pancreatic tail (Pt) tumors, lymph nodes along the celiac axis and common hepatic artery had a zero EI, although regional. When the Ph was segmented into the pancreatic neck (Ph-neck), uncinate process (Ph-up), and periampullary regions, hepatoduodenal ligament lymph nodes had a zero EI for Ph-up, although regional; the mesojejunum lymph node also had a zero EI, even for Ph-up, regardless of a high incidence of metastasis. Regarding lymph node recurrence after surgery, recurrence was most frequently found at the peri-Ph lymph node (12%) in patients with Pb tumors who had undergone a distal pancreatectomy.

CONCLUSIONS

The optimal extent of lymph node dissection should be estimated in regard to the tumor location.