Incidence of micrometastases in histologically negative para-aortic lymph nodes in advanced cervical cancer patients

Objective: Aims of the study were to identify the incidence of micrometastases in negative para-aortic lymph nodes, and to assess the utility of ultrastaging in histologic evaluation of para-aortic lymph nodes. Material and methods: Patients with advanced cervical cancer and negative para-aortic lymph nodes after routine histology examination were included. Paraffin-embedded tissue blocks were cut into 5-mu m-thick slides at step serial sections at 200-mu m intervals until there was no lymph node tissue left. 7 to 14 slides were obtained per lymph node and an immunohistochemistry staining with anti-cytokeratin antibody (EA1/EA3) was performed. Results: 581 histologically negative aortic nodes of 24 patients with advanced cervical cancer were assessed for para-aortic micrometastases (PAM). The incidence of micrometastases by the total number of studied lymph nodes was 0.003%. PAM were identified in 2 patients (8.3%), and additional submicrometastases were also found in one of them (4.1%). A single metastatic cluster of less than 0.2 mm was found in an afferent lymphatic vessel of another patient, not considered as a submicrometastases. PAM incidence was too low to allow for evaluation of associated risk factors, and for analysis of prognostic significance. Conclusion: Although examination of PAM with ultrastaging and IHC is expensive and time-consuming, and difficult to be routinely applied to all negative lymph nodes retrieved in a para-aortic lymphadenectomy, this study adds to current evidence that removal of aortic nodes may benefit a subgroup of advanced cervical cancer patients with PAM and negative aortic lymph node at imaging techniques including PET-scan. (C) 2010 Published by Elsevier Inc.