Elisa Detection of Salivary Levels of Cd44sol as a Diagnostic Test for Laryngeal Carcinomas

Abstract

Background: The soluble fraction of the CD44 protein (CD44sol) appears to be a possible candidate screening marker for the early diagnosis of head and neck tumors. The aim of our study was to ascertain the levels of CD44sol in the saliva of patients with laryngeal carcinoma and compare them with those of a control group of individuals to assess the reliability of the test as diagnostic marker. Methods: Ninety-two individuals with suspected laryngeal cancer who were submitted to biopsy were selected for the study. Forty adults who underwent surgery for head and neck benign disease were recruited to form a control group. The sampling of saliva was performed on the day before the laryngeal biopsy in the patient group and on the day before surgery in the control group. CD44sol levels were detected using the ELISA method. Results: The levels of CD44sol were significantly higher in the patient group than they were in the control group (31.4 ± 27.3 vs. 9 ± 7.1 ng/mL). CD44sol levels were not related to smoking and drinking habits. Analysis of the clinical data revealed an absence of significant differences between the study groups according to tumor site, histological grade, and clinical stage of T and N. The salivary levels of CD44sol were higher in advanced-stage (stages III and IV) compared with early-stage disease (43.2 ± 32.2 vs. 32.2 ± 20.5 ng/mL). Sensitivity and specificity were calculated based on the ROC curve and exhibited best accuracy using a predictive probability cut-off point of 10 ng/mL, with corresponding estimates of sensitivity and specificity of 89.5% and 83.3%, respectively. Discussion: The determination of CD44sol levels in the saliva of patients with laryngeal carcinoma using ELISA seems to be a promising diagnostic test in terms of high sensitivity and specificity, low cost and noninvasiveness of the technique.