Periodontal Disease and Incidence of Cancers: A Systematic Review and Meta-analysis of Cohort Studies

Associations between periodontal disease (PD) and cancers risk have been described previously, but the evidence remains inconclusive. This study aimed to investigate the association between PD and specific cancers through a systematic review and meta-analysis. We searched PubMed and Web of Science for English-language studies. Prospective and retrospective cohort studies were included. Three reviewers independently assessed study eligibility, extracted data, and evaluated the quality of studies. Random or fixed effects models were used to assess the association between PD and cancers. Stratified analyses by PD assessment methods, follow-up duration, and geographic region were conducted. A total of 8816 articles were identified, and 26 cohort studies met the inclusion criteria. Positive association between PD and multiple cancers, including pancreatic cancer (RR = 1.26, 95% CI: 1.03-1.52), bladder cancer (RR = 1.21, 95% CI: 1.11-1.32), esophageal cancer (RR = 1.34, 95% CI: 1.04-1.71), prostate cancer (RR = 1.17, 95% CI: 1.07-1.29), colorectal cancer (RR = 1.16, 95% CI: 1.01-1.34), gastric cancer (RR = 1.16, 95% CI: 1.08-1.25), and breast cancer (RR = 1.11, 95% CI: 1.03-1.17). Stratified by PD assessment methods, self-reported PD was positively associated with colorectal cancer (RR = 1.28, 95% CI: 1.01-1.62), gastric cancer (RR = 1.34, 95% CI: 1.11-1.63), lung cancer (RR = 1.19, 95% CI: 1.09-1.31), bladder cancer (RR = 1.26, 95% CI: 1.12-1.43), and pancreatic cancer (RR = 1.42, 95% CI: 1.03-1.96). Clinically examined PD only linked to gastric cancer (RR = 1.11, 95% CI: 1.04-1.16). PD was associated with colorectal, gastric, bladder, pancreatic, esophageal, and breast cancers. Self-reported and clinically examined PD differed slightly in effect magnitudes, yet the direction of associations remained consistent.