The impact of timing and modalities of dental prophylaxis on the risk of 5-fluorouracil–related oral mucositis in patients with head and neck cancer: a nationwide population-based cohort study

Purpose: This study investigated the impact of dental prophylaxis on 5-fluorouracil (5-FU)–related oral mucositis (OM) according to the head and neck cancer (HNC) locations and treatment times. Methods: A total of 13,969 HNC participants, including 482 5-FU–related OM subjects and 13,487 comparisons were enrolled from the Longitudinal Health Insurance Database for Catastrophic Illness Patients of Taiwan between 2000 and 2008. All subjects were stratified into subgroups based on the times to perform chlorhexidine use, scaling, and fluoride application before 5-FU administration. The dental prophylaxis related to 5-FU–related OM was estimated by multiple logistic regression and represented with odds ratio (OR) and 95% confidence interval (CI). Results: Fluoride gel application and scaling significantly impacted on OM development (p < 0.001), and the joint effect of fluoride gel and scaling induced 5-FU–related OM (OR = 3.46, 95% CI = 2.39–5.01). The risk of OM was raised 2.25-fold as scaling within 3 weeks before 5-FU–related chemotherapy (95% CI = 1.81–2.81), and a 3.22-fold increased risk of OM while fluoride gel was applied during 5-FU–related treatment (95% CI = 1.46–7.13). Conclusion: Dental prophylaxis significantly affected 5-FU–related OM in the HNC population. A short interval between dental scaling or fluoride application and 5-FU administration may be associated with higher prevalence of OM. Scaling simultaneously combined with chlorohexidine promoted 5-FU–related OM in specific HNC patients excluding the oral cancer and nasopharyngeal cancer population. Proper timing of the prophylactic dental treatments prior to 5-FU therapy could reduce the risk to develop 5-FU–related OM.