The association between periodontal disease and breast cancer in a prospective cohort study
Menée aux Etats-Unis à partir de données 2003-2017 de la cohorte "Sister study" portant sur 49 968 femmes (âge : 35-74 ans ; durée moyenne de suivi : 9,3 ans), cette étude analyse l'association entre une maladie parodontale et le risque de cancer du sein (3 339 cas)
Periodontal disease may be associated with increased breast cancer risk, but studies have not considered invasive breast cancer and ductal carcinoma in situ (DCIS) separately in the same population. We assessed the relationship between periodontal disease and breast cancer in a large prospective cohort study. The Sister Study followed women without prior breast cancer aged 35-74 years from 2003-2017 (N=49,968). Baseline periodontal disease was self-reported, and incident breast cancer was ascertained over a mean follow-up of 9.3 years. We estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards regression, adjusting for multiple potential confounders, including smoking status. Heterogeneity in risk for invasive breast cancer versus DCIS was also estimated. About 22% of participants reported a history of periodontal disease at baseline. 3,339 incident breast cancers (2,607 invasive breast cancer, 732 DCIS) were identified. There was no clear association between periodontal disease and overall breast cancer risk (HR=1.02, 95% CI: 0.94-1.11). However, we observed a non-statistically significant suggestive increased risk of invasive breast cancer (HR=1.07, 95% CI: 0.97-1.17) and decreased risk of DCIS (HR=0.86, 95% CI: 0.72-1.04) associated with periodontal disease, with evidence for heterogeneity in the risk associations (relative HR for invasive breast cancer versus DCIS=1.24, 95% CI: 1.01-1.52). A case-only analysis for etiologic heterogeneity confirmed this difference. We observed no clear association between periodontal disease and overall breast cancer risk. The heterogeneity in risk associations for invasive breast cancer versus DCIS warrants further exploration.