Oral Candida colonization in oral cancer patients and its relationship with traditional risk factors of oral cancer: A matched case-control study
Introduction
Oral cancer, is the eighth most diagnosed cancer in Victorians in 2009 [1] and globally it ranks the 8th and the 13th most common malignancies for males and females, respectively [2]. The five-year survival rates are poor with 50% achieved only with optimal care [3]. Although the life quality for patients has been improved by surgical advances, overall mortality has not changed in the last 50 years [4]. Tobacco use and heavy alcohol consumption has been strongly associated with oral cancer [5]. Other postulated risk factors include poor oral hygiene [6], viral infections [7] and Candida albicans infections. Candida albicans has been associated with leukoplakic lesions and the presence of Candida species has been recognized as an independent risk factor for oral carcinoma [8].
Candida can cause a spectrum of oral mucosal lesions including chronic hyperplastic candidosis, (candidal leukoplakia). It has been postulated that this variant of oral candidosis carries a significant risk of malignant transformation [9], [10]. During the last four decades, increasing clinical and experimental evidence suggests a putative role for Candida in the multi-steps process of oral mucosal carcinogenesis. An aetiological role of Candida in causing progression to carcinoma was first suggested by Cawson in 1966 [11] with later reports suggesting a link between presence of C. albicans and oral squamous cell carcinoma [12], [13], [14], [15]. The most significant evidence is the increase in the frequency of C. albicans in biofilms from oral squamous cell carcinoma tumor sites compared to control areas [16] and the correlation between oral yeast carriage and the presence and degree of oral epithelial dysplastic and neoplastic changes [17].
To date there has not been a matched case-control study assessing all potential variables confounding oral cancer risk particularly regarding oral Candida colonization in oral cancer patients. Thus, this study aimed to firstly: isolate, identify and genotype oral yeasts from oral cancer patients and matched oral cancer-free subjects. Second, this study aimed to elucidate the association, if any, of oral Candida colonization with other known risk factors for oral cancer. We hypothesized that certain species, or strains, of Candida are associated with the presence of oral cancer and that Candida oral carriage and high level of colonization are risk factors in oral cancer.
Section snippets
Patient samples
Ethical approval was granted by the Human Research Ethics Committees of Melbourne Health (approval number 2012.133), Dental Health Services of Victoria (approval number 254) and Melbourne University (ethics ID 1238737). All patients gave informed consent prior to being enrolled in the present study. A total of 52 consecutive oral cancer patients and 104 age (±three years), gender and denture status (with or without denture) matched non-oral cancer control subjects were enrolled from October
Patients’ demographics
A total of 154 patients were enrolled in this study, 52 oral cancer patients (27 males and 25 females) and 104 non-oral cancer controls (54 males and 50 females). The median age was 61 years with a range of 23–88 years. The frequency of cancer sites in oral cancer patients (n = 52 patients) was: 18 (34.6%) tongue, 13 (25%) buccal mucosa, 11 (21.2%) floor of mouth, 5 (9.6%) retromolar area and 5 (9.6%) gingiva and labial mucosa.
No significant differences were found between oral cancer and non-oral
Discussion
The present study is the first matched case-control study to assess the diversity of Candida species and strains colonizing the oral cavity of oral cancer and non-oral cancer patients. In addition, it is the first comprehensive investigation of the association of oral Candida carriage and level of oral yeast colonization with oral cancer occurrence after a statistical adjustment of relevant risk factors such as tobacco smoking, alcohol drinking, medical problems (such as HPV and HIV
Conflict of Interest Statement
None declared.
Acknowledgement
This work was supported by Grant from Oral Health CRC (Cooperative Research Centre) of the Melbourne Dental School, The University of Melbourne.
References (43)
Oral squamous cell carcinoma; from an hypothesis about a virus, to concern about possible sexual transmission
Oral Oncol
(2002)Chronic oral candidiasis and leukoplakia
Oral Surg Oral Med Oral Pathol
(1966)- et al.
The prevalence of Candida albicans in the mouths of tobacco smokers with and without oral mucous membrane keratoses
Oral Surg Oral Med Oral Pathol
(1982) - et al.
The microflora associated with human oral carcinomas
Oral Oncol
(1998) - et al.
Oral yeast carriage correlates with presence of oral epithelial dysplasia
Oral Oncol
(2002) Infectious and dietary risk factors of oral cancer
Oral Oncol
(2010)- et al.
Relationship between dental factors and risk of upper aerodigestive tract cancer
Oral Oncol
(1998) - et al.
Pathways connecting inflammation and cancer
Curr Opin Genet Develop
(2008) - Cancer Council Victoria, Cancer Epidemiology Centre 2011. CANSTAT: cancer in Victoria; 2009....
- et al.
Global cancer statistics, 2002
CA: Cancer J Clin
(2005)
Global oral health inequalities in incidence and outcomes for oral cancer: causes and solutions
Adv Dent Res
A comprehensive review of oral cancer
Gen Dent
Tobacco use and oral cancer: a global perspective
J Dent Educ
Smoking, alcohol, diet, dentition and sexual practices in the epidemiology of oral cancer in Poland
Eur J Cancer Prev
Leukoplakia and oral cancer
Proc Roy Soc Med
Classification of oral candidosis
Differential invasion of Candida albicans isolates in an in vitro model of oral candidosis
Oral Microbiol Immunol
Occurrence of Candida in oral leukoplakias
Acta Pathol Microbiol Scand B Microbiol Immunol
Candida in oral leukoplakias. A histologic and exfoliative cytologic study
Scand J Dent Res
The presence of Candida in 723 oral leukoplakias among Indian villagers
Scand J Dent Res
Case-control studies: design, conduct, analysis
Cited by (103)
Alcohol consumption modulates Candida albicans-induced oral carcinogenesis and progression
2023, Journal of Oral BiosciencesBioinspired gold coated phage nanosomes for anti-microbial and anti-cancer theranostics
2023, Materials Today NanoIs Candida albicans a contributor to cancer? A critical review based on the current evidence
2023, Microbiological ResearchOral dysbiosis in the onset and carcinogenesis of oral epithelial dysplasia: A systematic review
2023, Archives of Oral Biology