Fusobacterium nucleatum in the Colorectum and Its Association with Cancer Risk and Survival: A Systematic Review and Meta-analysis

BACKGROUND: The gut microbiome, in particular Fusobacterium nucleatum, has been reported to play a role in colorectal cancer development and in patient prognosis. We aimed to perform a systematic review and meta-analysis of published studies to assess the prevalence of F. nucleatum in colorectal tumors and evaluate the association between F. nucleatum and colorectal cancer development and prognosis. METHODS: MEDLINE, EMBASE, and Web of Science databases were systematically searched for studies published until January 2019. Random effects meta-analyses were used to assess the prevalence of F. nucleatum in patients with colorectal cancer or tissues relative to controls and survival in F. nucleatum-positive versus -negative patients. RESULTS: Forty-five relevant articles were identified. Meta-analyses indicated higher odds of F. nucleatum being present in colorectal tissue samples from patients with colorectal cancer [n = 6 studies, pooled OR = 10.06; 95% confidence intervals (CI), 4.48-22.58] and individuals with colorectal polyps (n = 5 studies, pooled OR = 1.83; 95% CI, 1.07-3.16) compared with healthy controls. Similar results were apparent in fecal samples, and when comparing tumor with adjacent normal tissue. Meta-analyses indicated poorer survival in patients with colorectal cancer with high versus low F. nucleatum abundance (n = 5 studies, pooled HR = 1.87; 95% CI, 1.12-3.11). CONCLUSIONS: A consistent increase in the prevalence and/or abundance of F. nucleatum in col...