Analysis of paraaortic lymph node involvement in pancreatic carcinoma: a significant indication for surgery?

Lymph node status is a key prognostic factor for pancreatic carcinoma. The paraaortic lymph nodes are the highest level of lymph nodes that can be resected safely in the abdomen for pancreatic and other gastrointestinal tumors. The pattern of paraaortic lymph node involvement and its relation with other lymph node groups were analyzed and the significance of this information relative to surgical therapy examined.

Between 1974-1996, 99 patients with invasive ductal carcinoma of the pancreas underwent pancreatectomy at the study institution. The pattern of lymph node involvement, particularly paraaortic, was evaluated by careful pathologic review of extended lymphadenectomy specimens. RESULTS. Fifty-eight of 76 patients (76%) with carcinoma in the pancreatic head (Ph) and 19 of 23 patients (83%) with carcinoma of the pancreatic body and tail (Pbt) had lymph node involvement. Fourteen patients with Ph disease (18%) and 4 with Pbt disease (17%) had paraaortic lymph node involvement. Tumor size did not correlate with paraaortic lymph node involvement. A correlation was found between Group 13 (posterior pancreaticoduodenal lymph nodes), Group 14 (lymph nodes surrounding the superior mesenteric artery), and the paraaortic lymph nodes for Ph disease. All paraaortic lymph node metastases were located in the 16M region (the region between the celiac trunk and the inferior mesenteric artery). For patients with Pbt disease, the distribution of paraaortic lymph node metastases was the same as for those with Ph disease. Only 33% of cases of paraaortic lymph node metastases were suspected preoperatively or perioperatively. The longest survival for a patient with paraaortic lymph node metastases was 36 months and 17 months, respectively, for patients with Ph and Pbt disease.

The paraaortic lymph nodes are frequent sites of metastasis from pancreatic carcinoma, and are difficult to evaluate preoperatively or perioperatively. This situation mandates paraaortic lymph node dissection, at least in the 16M region.