Search for microbial markers of oral cancer in Fanconi Anemia

Fanconi anemia (FA) is a genetic disorder that leads to increased cancer predisposition due to hypersensitivity to DNA damage. FA patients develop oral squamous cell carcinoma much earlier and more frequently than the general population. Previous studies have suggested an association between oral microorganisms and cancer.

 Objectives: to examine the salivary microbiota of FA patients and their non-FA relatives.

 Methods: Levels and proportions of 108 microbial taxa were determined in unstimulated whole saliva using checkerboard DNA- DNA hybridization. Prevalence of uncultivated/unrecognized was assessed using the human oral microbial identification microarray (HOMIM). Significant differences between groups were sought using the Mann-Whitney test.

 Results: FA patients (n=18) were younger (mean age± SD; 18.9±9.8 years) than non-FA subjects (n=8) (32.1±19.8), but gender distribution was similar (61% and 62%females, respectively). FA patients presented higher microbial load (mean total DNA probe counts ± SD; 187.2 x10^5±97.8) than non-FA individuals (155.2 x10^5±93.7). The most numerous taxa were (FA vs. non-FA; mean counts x 10^5 ± SD) Neisseria mucosa (23.4±24.8 vs. 18.9±21.3), Veillonella dispar (14.0±10.0 vs. 10.2±6.4), Prevotella tannerae (12.1±7.5 vs. 10.5±5.6), Helicobacter pylori (9.8± 5.3 vs. 7.8±3.8) and Candida albicans (6.4±4.0 vs. 4.5±2.1). Porphyromonas endodontalis cell counts were higher in FA (3.5±1.5 vs. 0.9±0.6, p<0.05). Differences in mean %DNA probe count (± SD) were observed for P. endodontalis (2.4±2.2 vs. 0.5±0.3), Streptococcus sobrinus (2.3±0.6 x 1.8±0.5) and Enterobacter agglomerans (1.8±0.1 vs. 2.3±0.4) (p<0.05) (FA vs. non-FA, respectively). Among uncultivated/unrecognized taxa, Synergistetes sp. oral taxon (ot) 360 and Capnocytophaga sp. ot 335 were present in 100% of FA samples, Haemophilus sp. ot 036 in 35.7% and Prevotella sp ot 308 and 309 and Capnocytophaga sp ot 324 were present in 7.1%.

 Conclusions: There were differences in the salivary microbiota between FA and non FA. These findings might provide insights into the role of microorganisms in oral cancer.