Features and influencing factors of lymph node metastasis of pancreatic head cancer

Objective To investigate the features of lymph node metastasis of pancreatic head cancer and explore its influencing factors. Methods Operative microscopy was applied in 24 cases after radical surgery of the pancreatic head cancer to find lymph nodes. Then the lymph nodes were grouped in detail and the metastatic frequency of each group was compared. The relationship between lymph node metastasis and other clinical or pathological factors were explored. Results The mean number of examined lymph node was 37.7/patient. Lymph node metastasis was found in 17 cases. The most common sites of lymph nodes involved were No. 13,No. 14,No. 12 and No. 8. Four pancreatic cancer derived from the uncinate process had superior mesenteric vessel lymph node metastasis but no post-pancreatoduodenal lymph node involvement. Most of the involved lymph nodes of paraaortic region were located in the triangular area surrounded by the abdominal aorta,inferior vena cava and left renal vein. There was no significant relationship between lymph node metastasis and the primary tumor size or histological type. Elevated preoperative serum levels of CA_ 50 and CA_ 24-2 were correlated to the lymph node metastasis. Conclusions In case of radical cancer resection,extensive lymph node dissection is necessary even if the tumor is localized within the pancreas. More attention should be paid to the lymph nodes around the superior mesenteric vessel,especially when the tumor is derived from the pancreatic uncinate process. It is important to clear the lymph nodes in the triangular area surrounded by the abdominal aorta,inferior vena cava and left renal vein. Elevated preoperative serum levels of CA_ 50 and CA_ 24-2 means that the pancreatic head cancer might have lymph node involvement.