[Oral candida species distribution in patients receiving radiotherapy for head and neck cancer].

Purpose: To investigate the distribution of oral candida species in head and neck cancer (HNC) patients treated with radiation therapy, and provide the basis for planning of clinical preventive measures.

Methods: Saliva was sampled from 60 HNC patients before, during and after radiation. Concomitantly, 60 healthy individuals whose age and sex matched that of the patient group were selected as control group. Oral candida carriages were quantitatively detected and the different candida species were identified by multiple measures such as CHROMagar candida culture medium and API 20C AUX yeast identification system. Then the differences between the two groups in terms of the candida detection rate and the distribution of each species of candida were analyzed with SPSS 17.0 software package.

Results: Xerostomia and dysphagia was found in 54 HNC patients during radiotherapy, radiation-induced oral mucotitis(RIOM) was found in 50 HNC patients,and oral candidiasis was found in 18 HNC patients; In radiation group, the detection rate of candida colonization during radiation was 56.7%, 63.3% postradiation, which showed significant differences compared with pre-radiation (X² =18.320,P<0.001 ); Among the 54 identified clinical isolates, candida albicans (n=42) was the most frequent, followed by candida parapsilosis (n=6), candida tropicalis (n=4) and candida glabrata (n=2). In radiation group, the oral candida pathogens detection rate was 30%, and candida colonization was 46.7%.

Conclusions: The oral candida colonization rate was significantly higher in HNC patients after radiotherapy, which indicated that the candida infection may be closely related to RIOM.