Abstract POSTER-CTRL-1201: Periodontal bone loss and risk of epithelial ovarian cancer in nurses’ health study
Authors: Babic Ana , Poole Elizabeth M. , Terry Kathryn L. , Tworoger Shelley S. 
Published: August 2015

Abstract
Introduction: Epidemiologic and biomarker studies suggest that inflammation is associated with ovarian cancer. Periodontal disease is an inflammatory response to microbial biofilms in dental plaque, affecting 30-35% of adult US population and potentially leading to loss of periodontal bone tissue and teeth loss. It is associated with several inflammation-related diseases, including cardiovascular disease, lung cancer, and pancreatic cancer. In this study we investigated the association between periodontal bone loss, a marker for advanced periodontal disease, and risk of epithelial ovarian cancer, in the Nurses’ Health Study, a prospective cohort of US-based nurses.
Methods: Periodontal bone loss was self-reported by participants in 1998 and updated in 2000. This analysis included women with baseline information on periodontal bone loss, with no previous history of bilateral oophorectomy, pelvic radiation, or cancer (except non-melanoma skin cancer). Detailed information on relevant lifestyle and reproductive factors was updated every two years and participants were followed for incident ovarian epithelial cancer cases until June 2010. Relative risks (RR) and 95% confidence intervals (CI) for the association of periodontal bone loss with risk of ovarian cancer were assessed using Cox proportional hazards models adjusted for age and other potential confounders, listed below.
Results: During follow-up (1998-2010), 352 incident epithelial ovarian cancer cases were identified among the 55,554 women who provided information on periodontal bone loss in 1998. In the main analysis, adjusted for age, duration of oral contraceptive use, tubal ligation, parity and family history of ovarian or breast cancer, periodontal disease was associated with a suggestively decreased risk of ovarian cancer (RR: 0.83; 95% CI: 0.61-1.13). While there was no association (RR=1.51, 95% CI: 0.82-2.81) between periodontal bone loss and non-serous ovarian cancer, participants with periodontal bone loss were at significantly lower risk of serous ovarian cancer than those with no bone loss (RR=0.64, 95% CI: 0.43-0.98). We observed no evidence of confounding by duration and type of menopausal hormone therapy, regularity of menstrual periods, diet quality (as measured by the alternative healthy eating index), physical activity, body mass index (BMI), diabetes, vitamin D status, NSAID use, smoking, or intakes of caffeine, alcohol, or lactose. The association was similar when stratifying by smoking, history of diabetes, use of hormone therapy, or BMI. History of periodontal bone loss was inversely associated with risk of ovarian cancer in women younger than 68 (median age; RR: 0.61, 95% CI: 0.36-1.00), but not in older women (RR: 1.09, 95% CI: 0.74-1.62)(P-heterogeneity = 0.08).
Conclusions: This is the first study to investigate the association between ovarian cancer and periodontal health. We observed that women with history of advanced periodontal disease, as reflected by periodontal bone loss, may be at decreased risk of serous ovarian cancer, particularly for younger women. Future studies should confirm these findings and investigate the underlying mechanism.
Citation Format: Ana Babic, Elizabeth M. Poole, Kathryn L. Terry, Shelley S. Tworoger. Periodontal bone loss and risk of epithelial ovarian cancer in nurses’ health study [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-CTRL-1201.