Purpose: Fusobacterium nucleatum (F. nucleatum) is a component of the human microbiome that primarily inhabits the oral cavity. It causes periodontal disease and has also been implicated in the development of human cancers. Although there are several reports of the relationship between F. nucleatum and the clinical outcome in human cancers, its prognostic significance in esophageal cancer remains unclear.
Experimental design: We quantified F. nucleatum DNA in 325 resected esophageal cancer specimens by qPCR. Significant pathways in F. nucleatum-positive esophageal cancer tissues were identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis using microarray data.
Results: Esophageal cancer tissues contained significantly more F. nucleatum DNA than matched normal esophageal mucosa (P = 0.021; n = 60). F. nucleatum DNA was detected in 74 of 325 cases (23%). F. nucleatum DNA positivity was significantly associated with tumor stage, but not with sex, age, performance status, tobacco use, alcohol use, histology, tumor location, or preoperative treatment. F. nucleatum DNA positivity was also significantly associated with cancer-specific survival [log-rank P = 0.0039; univariate HR = 2.01; 95% confidence interval (CI), 1.22-3.23; P = 0.0068; multivariate HR = 1.78; 95% CI, 1.06-2.94; P = 0.031]. The top-ranked KEGG pathway in F. nucleatum-positive tissues was "cytokine-cytokine receptor interaction." A significant relationship between F. nucleatum and the chemokine CCL20 was validated by IHC.
Conclusions: F. nucleatum in esophageal cancer tissues was associated with shorter survival, suggesting a potential role as a prognostic biomarker. F. nucleatum might also contribute to aggressive tumor behavior through activation of chemokines, such as CCL20. Clin Cancer Res; 22(22); 5574-81. ©2016 AACR.
©2016 American Association for Cancer Research.