Immunohistochemical analysis of pelvic lymph node micrometastases in cervical cancer patients with histologically negative nodes

Objective：The purpose of this study was to identify, by immunohistochemistry, possible micrometastasis in the pelvic lymph nodes previously considered free by conventional histopathological examination, and to assess their influence on the survival of patients with cervical cancer. Methods：This retrospective study included patients (n=51) operated on between February 2001 and May 2004 for cervical cancer without histopathologic lymph node involvement. Lymph nodes (n=282) from 51 patients with histologically node-negative cervical cancer were evaluated for micrometastasis. These were submitted to immunohistochemical study using AE1/AE3 anti-cytokeratin monoclonal antibodies to identify neoplastic epithelial cells. Results：The mean age of the patients was 45.3 years (range, 27-72). Lymph node micrometastases were immunohistochemically detected in 3 of the 51 patients (5.9%), comprising 3 of 282 (1.1%) pelvic lymph nodes examined. One patient (Ib2) had adenocarcinoma and others (Ib1,Ib2), squamous cell carcinoma. All of them had negative lymph-vascular space invasion. In three patients, there were recurrences (66.7%, 2/3), and one patient (Ib1) died from the pelvic recurrence. Conclusion：We recommend an immunohistochemical examination for lymph node micrometastases in cervical cancer patients with histologically negative nodes. This immunohistochemical method can be employed successfully in the detection of neoplastic cells in lymph nodes previously considered free. Micrometastasis could provide important information for further treatment strategies and follow up. Its clinical significance in cervical cancer warrants further study.