Salivary biomarkers and microbial attributes in oral health of nasopharyngeal-carcinoma

Abstract

OBJECTIVES: Nasopharyngeal carcinoma (NPC) is one of the commonest cancers in South East Asia. In the present prospective translational study, we monitored the oral health of NPC patients under Intensity Modulated Radiation Therapy (IMRT) in terms of oral candidiasis and salivary biomarkers. The preliminary data of the study were communicated at IADR-SEA, 2011, Singapore (Joseph Lister Award, 2011). Herein we report the data after the study completion. METHODS: Newly diagnosed 47 non-metastatic NPC patients were recruited into the study. Saliva samples and oral rinse samples were collected at baseline and during the IMRT at 2, 4, 6 weeks and 2 months post-radiotherapy. Oral rinse samples were examined for speciation, antifungal resistance and virulence attribute of Candida species. Salivary samples were analyzed for innate host defense biomarkers i.e. IL-6, IL-8, TNF-α, IL-1β-IL-1ra and immunoglobulins IgA and IgE. Demographical data of the patients and details of radiotherapy were also recorded. RESULTS: Salivary biomarkers IL-6, IL-8, TNF-α, IL-1β levels correlated well with the course of IMRT in NPC patients showing gradual increase from the base line and a drop at the end of the treatment. For instance mean IL-6 levels were 36.8, 339.8, 526.4, 703.6 and 114.5 pg/mL at the base-line to 2 month post-radiotherapy. Candidal carriage and clinical candidiasis peaked at 2 weeks in IMRT. C. parapsilosis was found to be a major species in post-radiotherapy and exhibited higher biofilm formation ability. Interestingly, mixed Candida species with higher drug resistance was also noted. CONCLUSIONS: This pioneering translational study has identified a potential salivary biomarkers and microbial attribute that could be used to monitor oral health of NPC patients under IMRT. Early intervention with an appropriate antifungal regimen appears desirable to mitigate oral candidiasis and oral inflammation in NPC patients.