Active periodontal inflammation and lymph node metastasis in breast cancer

This study aimed to investigate the relationship between periodontal inflammation and lymph node metastasis in breast cancer. This cross-sectional study included 71 newly diagnosed breast cancer patients who underwent periodontal examination including probing pocket depth, clinical attachment level, plaque index, gingival index, bleeding on probing, periodontal epithelial surface area and periodontal inflamed surface area. Salivary and serum IL-1β, IL-6, IL-10, MCP-1, RANTES, and ENA-78 were quantified by ELISA. Patients were stratified according to lymph node status [LN (–)/LN (+)] and periodontal disease severity. Single explanatory variable logistic regression analysis was performed to evaluate the association between clinical variables and lymph node metastasis. Demographic characteristics and periodontal disease severity were comparable between LN (-) and LN (+) patients. In exploratory subgroup analyses, patients with stage III–IV periodontitis in the LN (+) group exhibited a higher prevalence of periodontal pocket depth ≥ 4 mm with bleeding on probing (BOP/PPD4+) compared with LN (-) patients ( p < 0.001). Logistic regression analysis revealed that periodontal pocket depth ≥ 4 mm with bleeding on probing was significantly associated with lymph node metastasis (OR = 1.075; 95% CI:1.033–1.132; p = 0.002), whereas other clinical and demographic variables showed no significant associations. Salivary and serum inflammatory biomarkers did not differ according to lymph node status. The findings suggest that active periodontal inflammation, characterized by bleeding sites with probing pocket depth ≥ 4 mm in patients with severe periodontitis, may be associated with lymph node metastasis in breast cancer. These observations highlight the potential relevance of periodontal evaluation in breast cancer patients.