Oral Candida colonization in xerostomic postradiotherapy head and neck cancer patients

To evaluate (a) oral colonization of Candida species, especially for non-albicans Candida species (NACS), in xerostomic postradiotherapy head and neck cancer patients and (b) risk factors affecting their colonization.

Subjective and objective dry mouth scores, stimulated salivary flow rates, pH and buffering capacity were measured in 72 xerostomic postradiotherapy head and neck cancer patients. Candida counts and species identification were performed using oral rinse samples cultured in Candida Chromagar, followed by polymerase chain reaction and API 20C AUX system.

Candida colonization was observed in 87.5% of subjects, with 80.6% and 48.6% of study population colonized by C. albicans and NACS, respectively. NACS was associated with high objective dry mouth scores, denture use, and females (p = .006, .009, and .036, respectively). In addition, Candida glabrata was detected more in females (p = .018) and denture wearers (p = .026), while Candida tropicalis was associated with high objective dry mouth scores (p = .022) and females (p = .027). Quantity of Candida colonization correlated positively with objective dry mouth scores (r = 0.599, p < .001) and negatively with salivary flow rates (r = -0.258, p = .041) and pH (r = -0.290, p = .022).

NACS colonization was common in xerostomic head and neck cancer patients. Increased signs of dry mouth, female and dental prostheses may promote NACS colonization.