366P - Pre-treatment oral fungal microbiome and nasopharyngeal carcinoma prognosis: A population-based cohort study in southern China

Background

Microbiome has been proposed as a promising prognostic biomarker in various types of cancer. Although recent microbiome studies have linked the bacterial microbiome in the oral cavity and nasopharynx to the prognosis of nasopharyngeal carcinoma (NPC), the clinical significance of oral mycobiome, another key player of the oral microbiome, in NPC survival remain unknown.

Methods

We enrolled 476 untreated incident NPC patients from Wuzhou, southern China during March 2010 and December 2013, with follow-up through December 2018. We collected saliva samples at the time of diagnosis and characterized the oral mycobiome using fungal internal transcribed spacer (ITS)-2 sequencing. We analyzed the relationship between oral mycobiome and the overall survival using Cox regression adjusting for multiple confounders.

Results

Overall, the average follow-up of the NPC patients [mean (SD) age, 48.5 (10.7) years; 72% male) was 5.26 years. Patients with lower oral fungal alpha diversity (measured by observed features) had an inferior 5-year overall survival rate (lower group vs. higher group = 54.9% vs. 69.6%, P for log-rank test = 0.007). We found that lower alpha diversity was associated with an increased mortality [lower vs. higher: observed features (fully adjusted hazard ratio [HR] = 1.56, 95% confidence interval [CI] = 1.08-2.25); Simpson diversity (1.50, 1.04-2.15); Shannon diversity (1.79, 1.25-2.56)]. The associations were attenuated when further adjusted for cancer stage at diagnosis, and the significant associations were found only among localized-tumor-stage patients.

Conclusions

Oral mycobiome is a potential prognostic biomarker for patients with NPC and might provide potential guidance for treatment decision.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

The original field work was supported by a grant from the National Cancer Institute at the US National Institutes of Health (grant number: R01 CA115873). This work was supported by the Swedish Research Council (grant numbers: 2015-02625, 2015-06268, 2017-05814, 2019-01429), and the High-level Talents Research Start-up Project of Fujian Medical University (grant numbers: XRCZX2017035 and XRCZX2020034), the National Natural Science Foundation of China (grant number: U22A20322). Yufeng Chen was also partly supported by a scholarship from China Scholarship Council (grant number: 201600160071).

Disclosure

All authors have declared no conflicts of interest.