Assessment of saliva and oral candidiasis levels 12, 24 and 36 months after radiotherapy in patients with head and neck cancer

Introduction: Hyposalivation is a serious complication during radiotherapy (RT) and it is one of the major risk factors for the presence of candidiasis. The aim of this study was to evaluate the salivary hypofunction during the different stages of RT, analysing its connection with the presence of candidiasis. Material and methods: A retrospective study was performed in 83 patients who had been diagnosed with head and neck tumours and who were undergoing RT treatment. Their salivary function was clinically analysed throughout the course of the RT treatment (before, during and after treatment) by means of the whole saliva test (WST), both unstimulated (WST-I) and stimulated (WST-II), and its relationship with candidiasis was evaluated using culture-based methods. Results: The WST-I before RT was 37.24 +/- 17.36 mm and the WST-II was 60.70 +/- 30.98 mm, with 47% of patients testing positive for candidiasis. The prevalence of candidiasis increased up to 55.8% during RT and it returned to similar pre-RT levels at the end of treatment (45.2%). A statistical significant relationship was found between low WST-I and candidiasis in the 1st (13.58 vs 20.78 mm), 3rd (18.06 vs 24.36 mm), 6th (16.83 vs 24.5) and 12th (16 vs 28.74 mm) months after RT; and this relationship was also detected for WST-II in the 1st (24.73 vs 41.26 mm) and 3rd (27.71 vs 39.91 mm) months after RT. Female sex was identified as an independent associated risk factor for mild hyposalivation before RT (OR = 6.50, CI: 95% 1.77-23.93, p = 0.005) and glandular hypofunction (OR = 3.01, CI: 95% 1.12-8.10, p = 0.029). Discussion: There is a clear relation between hyposalivation and the presence of candidiasis during and after RT. Larger studies must be performed in order to further elucidate this effect. (C) 2020 Elsevier Masson SAS. All rights reserved.