Methods: Forty-six patients with oral cancer attending the Ear, Nose, Throat Institute, Rajvithi Hospital, Bangkok, Thailand were included in the study. Thirty healthy controls were age and gender matched to the experimental group. Subjects were asked to rinse their mouth with 10 ml sterile saline solution for one minute. These samples were centrifuged and re-suspended in PBS. The re-suspended pellets were spread on two 6.5% Sabouraud dextrose agar plates and incubated at 37°C for 48 hours. The colonies on each plate were counted and the colony forming units (cfu/ml) were calculated.
Results: Levels of oral candidiasis between oral cancer patients and healthy control were significantly different (p=0.001). When levels of candidiasis of oral cancer patients with different risk factors (smoking, betel nut chewing, and drinking) were compared, we found that there was a significant difference (p=0.038). Multiple comparison test reveled that the difference in levels of candidiasis was between betel nut chewers and smokers (p=0.053) and between betel nut chewers and patients who drink (p=0.013). We also observed that the average candida load of smokers was 2,689.37 CFU/ml higher than that of patients who are drinkers, but the difference did not reach a significant level.
Conclusions: These results reveal that there is a relationship between oral candidiasis and oral cancer which is consistent with a report stating that candida infection can promote oral neoplasia. There is also a significant difference in oral candidiasis between oral cancer patients who have history of different risk factors.