Objectives: Since hematogeneous tumor cell dissemination is a key event in tumor progression we assessed the prognostic significance of disseminated tumor cells (DTCs) in BM and circulating tumor cells (CTCs) in peripheral blood (PB) from patients suffering from SCC of the oral cavity (OSCC).

Materials and methods: In total, 111 patients with OSCC were enrolled in the study. The CellSearch™-system was used to enumerate CTCs. BM was aspirated from the iliac crest, and mononuclear cells (MNCs) were enriched by Ficoll density gradient centrifugation. To detect DTCs, MNCs were immunostained with the pan-keratin antibody A45-B/B3. Results were correlated with clinicopathological parameters and clinical outcome such as recurrence and death during follow up time.

Results: Significant correlations could be found regarding the combinations of tumor size with CTCs ( p < 0.01), nodal status and DTCs ( p < 0.05), and distant metastasis with CTCs ( p < 0.01) and DTCs ( p < 0.01). Univariate and multivariate analyses revealed that CTCs and DTCs were significant and independent predictors of disease-free survival ( p < 0.001).

Conclusion: Both DTCs and CTCs are independent prognostic markers in OSCC patients, predicting relapse with higher sensitivity at various disease stages than routine staging procedures.