[Occurrence pattern and impact of lymph node micrometastasis in pancreatic head cancer]

Objective: To investigate the occurrence of lymph node micrometastasis in pancreatic head carcinoma and analyze its effect on the prognosis of patients. Methods: The lymph nodes in 40 patients who received pancreatoduodenectomy with regional lymphadenectomy were dissected by surgical magnification microscopy. The expression of cytokeration(AE1/E3) were detected by immunohistochemical staining in the pathologically negative lymph nodes. The frequency of lymph nodes metastases and micrometastases, as well as the relationship between metastasis and prognosis were analyzed. Results: 1 550 lymph nodes were dissected from 40 patients. Lymph node metastases was pathologically detected in 27 patients (67.5%) and in 199 lymph nodes(12.8%). No.13(24.1%, 68/282), No.14(18.1%, 58/321), No.12(12.7%, 31/245), No.16(12.3%, 30/243) and No.17(11.4%, 12/105) lymph nodes groups had higher frequency of metastases. Lymph node micrometastases was immunohistochemically detected in 6 patients and 130 lymph nodes. No.14(16.5%, 53/321), No.13(15.2%, 43/282), No.16(6.2%, 15/243), No.12(4.9%, 12/245) and No.8(5.0%, 7/141) lymph nodes groups had higher frequency of micrometastases. The total ratio of patients with postive lymph nodes invasion and the ratio of positive lymph nodes invasion were 82.5% and 21.2%. 11 patients survived more than one year. 29 patients died of recurrence or metastasis within 8~11 months after surgery. The 1-year survival rate was 27.5%. 1-year survival rate was 14.9% in HE (+ ) patients, and 33.3% in HE (-) AE1/E3 (+ ) patients (P=0.632). AE1/E3 (-) HE (-) patients had a 1-years survival rate of 71.4%, which was statistically higher than that in HE (+ ) group patients (P=0.010). Conclusions: AE1/E3 combined with pathological examination can significantly improve the detection rate of lymph nodes micrometastasis in pancreatic head carcinoma patients. Micrometastasis is commonly found in No 13, 14, 12, 16, 8 lymph nodes groups. Lymph nodes micrometastasis had a significant effect on the prognosis of patients. Special attention should be payed to No 13, 14, 16, 12, 17 lymph nodes groups during radical duodenopancreatectomy.