Periodontal bone loss and risk of epithelial ovarian cancer

Periodontitis, a chronic inflammatory response to pathogenic bacteria in the oral microbiome, is common among adults. It is associated with several medical conditions, including cardiovascular diseases, and potentially with esophageal, lung, oral, and pancreatic cancer. One of the proposed mechanisms behind these associations is systemic inflammation, which has also been implicated in ovarian cancer etiology. The aim of this study was to evaluate association between ovarian cancer and periodontal bone loss. The association between periodontal bone loss, a marker of periodontitis, and risk of epithelial ovarian cancer was estimated among 60,560 participants of the prospective Nurses' Health Study using Cox proportional hazards analysis. Competing risks analysis was used to estimate association by histologic subtype. We did not observe an increased risk of ovarian cancer among participants with periodontal bone loss (HR 0.86, 95 % CI 0.64-1.15). Among women younger than 69 years, periodontal bone loss was associated with a 40 % (HR 0.60, 95 % CI 0.36-0.98) decreased ovarian cancer risk, while there was no association in women older than 69 (HR 1.09, 95 % CI 0.75-1.58), although this difference did not reach statistical significance (p-heterogeneity = 0.06). We observed a suggestive decreased risk for serous tumors (HR 0.76, 95 % CI 0.53-1.09). The number of natural teeth and root canals, other metrics of oral health, were not associated with ovarian cancer risk. Our results do not support an increased ovarian cancer risk in women with periodontal bone loss; however, there was a significant decrease in risk in women younger than 69. Given the unexpected association between periodontal bone loss and ovarian cancer risk in younger women, further research is warranted.