Association between oral volatile sulfur compounds and tumor markers

Objective: Analysis of exhaled breath is a promising diagnostic method. Sampling of exhaled breath is non-invasive and can be performed as often as considered desirable. Sulfur-containing molecules in the oral cavity have been used as markers of various systemic conditions. The aim of this study was to investigate the association between volatile sulfur compounds (VSCs) in the oral cavity and tumor markers. Methods: We analyzed 174 subjects who visited Pusan National University Hospital Health Promotion Center for comprehensive health examination from April to September in 2008. This study was approved by the Institutional Review Board for Human Subjects at the Pusan National University Hospital (approval number: 0740-155) and all of the subjects participated voluntarily with a written informed consent. All subjects completed physical and laboratory blood examination, a self-reported questionnaire, and oral examination. Hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide ((CH3)2S) were measured using the Oral Chroma®. Tumor markers (CA 125 in females, Prostatic Specific Antigen (PSA) in males, á-Fetoprotein (AFP), Carcino Embryonic cancer Antigen (CEA), and CA 19-9) were assessed in serum. Dependent variable was VSCs. Independent variables were tumor markers. ANCOVA and linear regression were applied to evaluate the association between VSCs and tumor markers controlling for age, gender, education, monthly household income, alcohol drinking, smoking, the frequency of tongue brushing and mouth breathing. Results: After controlling for all of the confounders, the H2S low group showed a significant lower CA 125 level than H2S high group (10.97±1.01 vs. 14.66±1.28). A significant linear relationships were found in the level of AFP with H2S and CA 125 with CH3SH. Conclusion: VSCs in the oral cavity were associated with some tumor markers. This might lead to a future diagnostic test for cancer. Further prospective molecular approach will be needed to clarify the causality and the biological pathway.