The prevalence rate of Porphyromonas gingivalis and its association with cancer: A systematic review and meta-analysis.

It seems that Porphyromanas gingivalis is carcinogenic, because it activates a number of inflammatory immune responses in the host and causes disorders in bacterial clearance mechanisms. There is little information on the prevalence of this bacterium in cancer patients. The aim of this study was to evaluate and compare the prevalence of P. gingivalis in cancer patients by meta-analysis methods.Different databases including PubMed, EMBASE, the Cochrane Library, Scopus, and ISI web of Knowledge were investigated and eight relevant articles published in 2000-2013 were finally analyzed. Data were analyzed by meta-analysis method, fixed effect model. I² statistics were calculated to examine the heterogeneity of papers. The information was analyzed by R and STATA Ver 12.2.A total of 711 people infected with P. gingivalis were included in this study. In total, the prevalence of P. gingivalis was 40.7% (95% CI, 19.3-62.1). The prevalence of P. gingivalis was evaluated in four case-control studies. The results of this study showed that P. gingivalis increased the chance of cancer development and periodontal disease as much as 1.36 times (OR, 1.36; 95%CI, 0.47-3.97).Although there was no significant correlation between P. gingivalis and cancer, this bacterium increased the chance of cancer and periodontal disease and could be considered as a main potential risk factor.