Increased Cyfra 21-1 concentration in saliva from primary oral squamous cell carcinoma patients

Background: Saliva is the body fluid in the oral cavity and contacts directly with oral mucosa. As a detective media, it is acceptable and non-traumatic. Cyfra 21-1, being the soluble fragment of cytokeratin 19(CK19), correlates well with oral squamous cell carcinoma (OSCC). Objective: To investigate the saliva Cyfra 21-1 concentrations in OSCC patients and healthy persons, and the correlation between the Cyfra 21-1 concentration in saliva and the CK19 expression in tissue from OSCC patients. Design: Saliva Cyfra 21-1 concentration was detected by ELISA in 30 OSCC patients and 30 healthy persons; CK19 protein expression and CK19 mRNA level were, respectively, detected by immunohistochernistry and fluorescent real-time RT-PCR in cancerous and paracancerous tissues from 33 OSCC patients. Results: Saliva Cyfra 21-1 concentration in OSCC patients (85.95 +/- 78.00 mu g/L) was significantly higher than that in healthy persons (42.27 +/- 40.84 mu g/L) (P = 0.009); it was also significantly higher in the patients suffering later tumour recurrence (130.95 +/- 66.38 mu g/L) than that in the patients without tumour recurrence (74.84 +/- 63.45 mu g/L) (P = 0.023). CK19 protein expression increased significantly in OSCC tissues (P < 0.001) with positive rate of 90.9%, CK19 mRNA level in cancerous tissues was 2.21 folds higher than that in paracancerous tissues (P = 0.020); significant correlation was found between tissue CK19 protein expression and tissue CK19 mRNA level (P = 0.003), and great correlation was found between tissue CK19 protein expression and saliva Cyfra 21-1 concentration (P = 0.051). Conclusions: The increased CK19 expression in OSCC tissues plays an important role in the increase of saliva Cyfra 21-1 concentration. Potential clinical value of saliva Cyfra 21-1 detection is suggested for OSCC. Further studies are encouraged to reveal the real diagnostic and prognostic value of detecting saliva Cyfra 21-1 concentration for OSCC. (C) 2007 Elsevier Ltd. All rights reserved.