Streptococcus and Prevotella are associated with the prognosis of oesophageal squamous cell carcinoma.

Purpose: Oesophageal squamous cell carcinoma (ESCC) is the dominant type of oesophageal cancer among the East Asian population. The role of ESCC tissue bacteria in neoplastic progression has not been fully elucidated. Our goal was to uncover different bacterial communities in pathological staging grouping of ESCC and to identify microorganisms that could predict the likelihood of prognosis.
Methodology: Tissue samples were obtained from 45 patients and assessed using 16S ribosomal RNA gene sequencing. Significant bacteria were selected to perform survival analysis and evaluate prognostic biomarker.Results/Key findings. We observed variations in the abundance of oesophageal flora among different pathological characteristics of ESCC. Phylum Bacteroidetes, Firmicutes and Spirochaetes showed significantly higher relative abundances among N+ (positive lymph node) patients when compared to N- (negative lymph node) controls, whereas Proteobacteria showed lower abundances in N+ patients. Both genera Prevotella and Treponema were more abundant in the N+ group. In regard to T stage, the abundance of only Streptococcus in T3-4 was significantly higher than that in T1-2, while the other genera showed no significance. On multivariable analysis adjusted for the effects of standard clinicopathological features, combined Streptococcus and Prevotella abundance retained its association with unfavourable survival (hazard ratio, 6.094; 95 % confidence interval, 1.072-34.646; P=0.042), suggesting that this may be an independent prognostic indicator for ESCC.
Conclusion: Combined Streptococcus and Prevotella abundance is regarded as an independent species prognostic biomarker in ESCC patients.