title: Oral Candida colonization in oral cancer patients and its relationship with traditional risk factors of oral cancer: a matched case-control study.
abstract: OBJECTIVE
  Candida, an opportunistic fungal pathogen, has been implicated in oral and oesophageal cancers. This study aimed to examine oral Candida carriage in 52 oral cancer patients and 104 age-, gender- and denture status-matched oral cancer-free subjects.
  
  
  METHODS
  We assessed general health, smoking and alcohol drinking habits, use of alcohol-containing mouthwash and periodontal status (community periodontal index of treatment needs). Yeasts were isolated using oral rinse technique and genetically identified via Real-Time PCR-High resolution melting curve analysis of conserved ribosomal DNA. Conditional and binary logistic regressions were used to identify explanatory variables that are risk factors for oral cancer.
  
  
  CONCLUSIONS
  The frequencies of oral yeasts' presence and high oral colonization were significantly higher in oral cancer than non-oral cancer patients (p=001; p=0.033, respectively). No significant difference in the isolation profile of Candida species was found between the two groups, except C. parapsilosis was more frequent in non-oral cancer group. Differences were noticed in the incidence of C. albicans strains where significantly more C. albicans genotype-A was isolated from cancer patients and significantly more C. albicans genotype-B isolated from non-cancer patients. Multiple regression analyses showed significant association with cancer observed for alcohol drinking (OR=4.253; 95% CI=1.351, 13.386), Candida presence (OR=3.242; 95% CI=1.505, 6.984) and high oral colonization (OR=3.587; 95% CI=1.153, 11.162). These results indicate that there is a significant association between oral cancer occurrence and Candida oral colonization and that the observed genotypic diversity of C. albicans strains may play a role in oral carcinogenesis.
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic 3010, Australia.
authors.forename: Ali D
authors.initials: AD
authors.lastname: Alnuaimi
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic 3010, Australia; Head and Neck Oncology, The Royal Melbourne Hospital, Melbourne, Vic 3010, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Wiesenfeld
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic 3010, Australia.
authors.forename: Neil M
authors.initials: NM
authors.lastname: O'Brien-Simpson
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic 3010, Australia.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Reynolds
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic 3010, Australia. Electronic address: m.mccullough@unimelb.edu.au.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McCullough
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002175:Candida / Q000302:isolation & purification*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D009062:Mouth Neoplasms / Q000382:microbiology*; D012307:Risk Factors; D055815:Young Adult
keywords: Acetaldehyde; Candida albicans; Case-controlled study; Oral cancer; Risk factors; Squamous cell carcinoma