Clinical significance of lymph node micrometastasis in ampullary carcinoma

本研究旨在探讨壶腹癌淋巴结微转移的临床意义。对50例壶腹癌患者行胰十二指肠切除加区域淋巴结清扫术。共1283个区域淋巴结（中位数，每例患者25个）进行了组织学检查的转移。明显转移定义为常规组织学检查中用苏木精和伊红检测到的转移。微转移定义为首先通过免疫组织化学用抗细胞角蛋白7和8的抗体检测到的转移。中位随访期为切除后119个月。27例患者90枚淋巴结有明显转移。12例患者的33个淋巴结微转移阳性，均伴有明显的淋巴结转移。有淋巴结微转移的患者有明显转移的淋巴结数量（中位数，3.5）比无明显转移的患者（中位数，0 ; p < 0.001）多。在淋巴结微转移患者中，远处淋巴结（上级肠系膜淋巴结、主动脉旁淋巴结）的明显转移更常见（分别为p = 0.001和p = 0.038）。在单变量（p < 0.0001）和多变量（相对危险度，5.085; p = 0.007）分析中，发现淋巴结微转移是一个强有力的独立预后因素。在27例有明显淋巴结转移的患者中，有淋巴结微转移的患者（中位生存时间为11个月）切除术后的结局明显差于无淋巴结微转移的患者（中位生存时间为63个月; p = 0.0009）。免疫组化检测到的淋巴结微转移表明密集的淋巴扩散，从而对壶腹癌患者的生存产生不利影响。

This study aimed to clarify the clinical significance of lymph node micrometastasis in ampullary carcinoma. Pancreaticoduodenectomy with regional lymphadenectomy was performed for 50 consecutive patients with ampullary carcinoma. A total of 1283 regional lymph nodes (median, 25 per patient) were examined histologically for metastases. Overt metastasis was defined as metastasis detected during routine histologic examination with hematoxylin and eosin. Micrometastasis was defined as metastasis first detected by immunohistochemistry with an antibody against cytokeratins 7 and 8. The median follow-up period was 119 months after resection. Overt metastasis was positive in 90 lymph nodes from 27 patients. Micrometastasis was positive in 33 lymph nodes from 12 patients, all of whom also had overt nodal metastases. Patients with nodal micrometastasis had a larger number of lymph nodes with overt metastasis (median, 3.5) than those without (median, 0 ; p < 0.001). Overt metastasis to distant nodes (superior mesenteric nodes, para-aortic nodes) was more frequent (p = 0.001 and p = 0.038, respectively) in patients with nodal micrometastasis. Nodal micrometastasis was found to be a strong independent prognostic factor on univariate (p < 0.0001) and multivariate (relative risk, 5.085; p = 0.007) analyses. From among the 27 patients with overt nodal metastasis, the outcome after resection was significantly worse in the patients with nodal micrometastasis (median survival time of 11 months) than in those without (median survival time of 63 months; p = 0.0009). Immunohistochemically detected lymph node micrometastasis indicates intensive lymphatic spread, and thus adversely affects the survival of patients with ampullary carcinoma.