Pretreatment Serum Levels of Soluble Cytokeratin Fragments (Cyfra 21-1, TPS, MonoTotal) in Relation to Clinical and Pathobiological Aspects of Head and Neck Squamous Cell Carcinomas

BACKGROUND/AIM: The aim of this study was to analyze the pretreatment cytokeratin serum levels in head and neck squamous cell carcinoma (HNSCC) by three assays in relation to selected clinicopathological characteristics in an effort to find diagnostic/prognostic biomarkers for HNSCC and determine the best assay. PATIENTS AND METHODS: In total, 46 patients with HNSCC with different subsite (oropharyngeal-21 cases, hypopharyngeal-4 and laryngeal-21) were included in this prospective study. MonoTotal, Cyfra 21-1, and TPS radioimmunoassay kits were used to analyze cytokeratin fragments serum levels. RESULTS: Statistically significant differences in serum levels of TPS and Cyfra 21-1 were found between low (stage I-II)- and high-stage (stage III-IV) tumors (p=0.0057; p=0.0138 respectively). Cyfra21-1 assay showed significant differences between tumors of different sites with prominent elevation being found in oropharyngeal carcinomas and between patients with p16 positive and p16 negative HNSCC (p=0.0242), being elevated in p16 positive tumors. CONCLUSION: The present study is the first to compare cytokeratin serum levels between various subgroups of HNSCC using three different assays. Cyfra 21-1 seems to be the most useful for clinical practice. The relation between elevated Cyfra 21-1 serum levels and p16 expression requires further investigation.