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

Abstract

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-μm-thick slides at step serial sections at 200-μm 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.