Oropharyngeal candidiasis during radiotherapy for head and neck cancer: an observational study on prevalence, pain, and risk factors.

PURPOSE: This study aimed to investigate the prevalence and risk factors of oropharyngeal candidiasis (OPC) and its pain associations during radiotherapy for head and neck cancer (HNC).

METHODS

This retrospective observational study included 65 patients undergoing radiotherapy for HNC. OPC was assessed during the early and late phases of radiotherapy by visual inspection and/or oral culture. Pain was quantitatively assessed using the maximum opioid dose (oral morphine equivalent dose [MED]). The MEDs of the patients with and without OPC were compared. Multivariate analysis was performed to identify the independent risk factors of OPC.

RESULTS

OPC was confirmed in 38 of 65 patients (58%) during radiotherapy. Visual inspection indicated OPC in only 9 of 65 patients (14%), with a low diagnostic rate of 24% (9/38). The median MED was significantly higher for the OPC (82.5 mg) than for the non-OPC (60.0 mg) group (P = 0.027). Multivariate analysis identified BMI < 22 (OR, 5.14 [95% CI 1.48-17.8]; P = 0.010) and mucositis grade ≥ 3 (OR, 5.17 [95% CI 1.60-6.7]; P = 0.006) as independent risk factors for OPC.

CONCLUSION

The prevalence of OPC during radiotherapy was 58%, and its rate of detection via visual inspection alone was low. Significant pain requiring high MED was accompanied by OPC. Therefore, early diagnosis by oral culture and appropriate intervention is crucial for patients with suspected OPC, such as those with low BMI and mucositis grade ≥ 3, to complete planned radiotherapy and maintain their quality of life.