FROM CLINICAL CANCER RESEARCH
Fusobacterium nucleatum, a component of the human microbiome, appears to be associated with shorter survival in esophageal cancer, according to new findings.
F. nucleatum, generally found in the oral cavity and associated with periodontal disease, may have a potential role as a prognostic biomarker, and it might also contribute to aggressive tumor behavior via activation of chemokines, the study authors suggest ( Clin Cancer Res. 2016 Oct. doi: 10.1158/1078-0432.CCR-16-1786 ).
“However, no studies to date have examined the prognostic impact of F. nucleatum in esophageal cancer,” wrote Kensuke Yamamura, MD, of the department of gastroenterological surgery, Kumamoto University, Japan, and colleagues. “In this study, we quantified F. nucleatum DNA in 325 resected esophageal cancer specimens by qPCR [quantitative polymerase chain reaction].”
They add that this is “the first study to provide the evidence for the relationship between F. nucleatum and poor prognosis in esophageal cancer.”
An assessment of F. nucleatum DNA in esophageal cancer tissues by qPCR assay showed that levels were higher in malignant tissue than in paired adjacent nontumor tissues (P = .021). The relative F. nucleatum DNA levels were also measured in samples from 325 esophageal cancer cases.
Within those samples, F. nucleatum was detected in 74 (23%) of 325 cases. F. nucleatum positivity was not associated with most clinicopathologic features including patient sex, year of surgery, preoperative performance status, smoking history, alcohol history, comorbidity, tumor location, histology, tumor size, or preoperative therapy (all P greater than .05). However, it was associated with tumor stage (P = .016), T stage (P less than .01), and N stage (P = .039).
There were a total of 112 deaths among the 325 esophageal cancer patients, with 75 specific to the disease. The median follow-up time for censored patients was 2.6 years.
Patients positive for F. nucleatum had significantly shorter cancer-specific survival (log rank P = .0039) and overall survival (log rank P = .046) as compared with those who were F. nucleatum negative. In an analysis of F. nucleatum DNA status by Cox regression analysis, patients who were positive had significantly higher cancer-specific mortality as compared with those who were negative (hazard ratio, 2.01; P = .0068). After the analysis was adjusted for clinical, pathologic, and epidemiologic features, F. nucleatum positivity was associated with significantly higher cancer-specific mortality (multivariate HR, 1.78; P = .032), and similar findings were observed for overall mortality.
Dr. Yamamura and his team had also hypothesized that F. nucleatum might contribute to aggressive tumor behavior by activation of chemokines, and they were able to confirm that the presence or absence of F. nucleatum was significantly associated with CCL20 expression status, which was identified as the most upregulated chemokine.
