Biomarkers of Oxidative Stress, Proliferation, Inflammation and Invasivity in Saliva from Oral Cancer Patients

Abstract

Cancer represents the main cause of death in the economically developed countries and the second cause of death in developing ones. Head and neck squamous cell carcinomas are the sixth most common malignancies worldwide with oral cavity and pharynx cancers being the most common. Saliva qualifies as one of the most suitable diagnostic fluids due to the non-invasivity nature, simple handling procedures, easy collection and storage and good cooperation with patient groups such as children or persons with disabilities. The aim of the present study is to assess the presence in saliva of several cancer biomarkers such as: tumor cells proliferation - Ki-67 Antigen and Squamous Cell Carcinoma Antigen (SCCA), inflammation - Interleukin-6 (IL-6), extracellular matrix collagen degradation - Matrix Metallo-proteinase-9 (MMP-9) and Tissue Inhibitor of Metalloproteinases 2 (TIMP-2), oxidative stress - total antioxidant capacity and uric acid. Both uric acid and total antioxidant capacity showed decreased levelsin the saliva of oral cancer patients. IL-6, Ki-67, SCCA and MMP-9 showed increased levels in the saliva of oral patients compared to the control group. Salivary TIMP-2 levels were also decreased in the patients group. We can conclude that salivary diagnosis has the potential of becoming a powerful tool in detecting and monitoring oral cancer patients.