Status of salivary human beta defensin-2 in oral potentially malignant disorders and oral cancer: Quest for a novel non-invasive biomarker

Abstract

Background: Oral cancer ranks sixth among all the types of cancers globally and contributes to significant mortality and morbidity. Inflammation is known to play an important role in tumorigenesis. Human Beta Defensins are a type of AMP that play a role as chemo attractive, antimicrobial, and antitumor agents and also act as immunomodulators. They have also been demonstrated in cancer cell lines. Beta defensins act as tumor suppressor genes by manipulating the tumor microenvironment. The existing literature on human beta defensin-2 activity is scarce. There exists no literature on the comparison of the level of salivary human beta defensin-2 between subjects with oral potentially malignant disorders and oral cancer. Saliva contains constituents that reflect the physiologic state of the body. This can be utilized for rapid and atraumatic diagnosis of diseases owing to its non-invasive nature of collection. Aims and Objectives: The aim of the present study was to assess the level of human beta defensin-2 in the saliva of subjects with oral potentially malignant disorders and oral cancer and compare them with levels in healthy subjects. Materials and methods: The study sample included 75 subjects who were divided into three groups consisting of healthy subjects, subjects with oral potentially premalignant disorders and subjects with oral cancer. Results: The mean salivary Human beta defensin-2 level in subjects with oral cancer was significantly higher than in healthy controls and subjects with oral potentially malignant disorders. The level was highest in the oral cancer group and least in the control group. This difference among the 3 groups was statistically significant. In the group with premalignant disorders, the variation in the level of salivary human beta defensin-2 according to the type of lesion was not statistically significant. Conclusion: This study highlights the diagnostic role of hBD-2 in saliva. The presence of Human beta defensin-2 in the saliva of healthy controls points to its role in the maintenance of mucosal integrity. Elevation in the level of hBD-2 in oral potentially malignant disorders and a further increase in oral cancer indicate the potential use of hBD-2 as a biomarker in early diagnosis of oral cancer. Use of saliva as the diagnostic fluid aids in establishing a non-invasive and atraumatic means of diagnosis.