Does periodontal disease have an association with prostate cancer?

Data sources The electronic databases PubMed, Embase and the Cochrane Oral Health Group's Trials Register up to 7 July 2020 were searched to identify eligible studies. Information sources in the grey literature were not cited.Study selection Cohort studies and case-control studies in English were selected by two reviewers independently. All articles had to include a control patient group (without periodontal disease) and a group with periodontal disease and both groups with prostate cancer outcomes. Also, all articles reported the hazard ratio (HR), relative risk (RR) or odds ratio (OR) estimates with their 95% confidence intervals (CIs).Data extraction and synthesis Data extraction and risk of bias assessments were performed by two reviewers independently and any disagreements between these authors were resolved through discussion or by consulting a third author. Data were synthesised qualitatively by the Newcastle-Ottawa Scale. RR with 95% CI was used as the pooled estimate to assess the association of periodontal disease and the risk of prostate cancer. When the outcome of interest was rare, it was considered that the OR approximated the RR (24). HR was also treated as RR when pooled in this meta-analysis. The heterogeneity across studies was evaluated by Q test (statistical significance was considered when P <0.1) and the I2 statistic (I2 ≥50% indicated significant heterogeneity).Results Seven studies were included in the meta-analyses, with four being prospective cohort studies and three retrospective cohort studies. All studies were of high quality except one study that was considered to be of moderate quality. Pooled estimates indicated that periodontal disease had a significant statistical relationship with the risk of prostate cancer (RR = 1.17; 95% CI = 1.07-1.27; P = 0.001). No significant heterogeneity across studies was observed (P = 0.383; I2 = 5.8%). The studies include Asian, European and American populations.Conclusions The authors of this review concluded that periodontal disease could be a possible risk for prostate cancer and that the male public, and clinicians, should be aware of the importance of maintaining good periodontal health.