Is Periodontal Disease a Red Flag for Breast Cancer Among Postmenopausal Female Smokers? An Update of the Last Decade

Abstract

Periodontal disease is characterized by a chronic inflammation produced in response to a disease-associated, multispecies bacterial community in the subgingival region. In recent years, interest has focused on the potential role of periodontal disease in cancer pathogenesis. In this review, we presented a summary showing a strong association between breast cancer and poor oral health, presence of periodontitis-associated bacteria, tooth loss, and clinical signs of periodontitis. Proinflammatory pathways are activated either by mono- or polymicrobial infections, resulting in an increase in the expression of proinflammatory molecules such as interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor (TNF)-α. In addition, it has been shown that several periodontitis-associated species induce the expression of genes related to cell proliferation, cell cycle, apoptosis, transport, and immune and inflammatory responses. Intriguingly, many of these pathways are linked to carcinogenesis. Among them, the activation of Toll-like receptors (TLRs) and antiapoptotic pathways (such as the phosphoinositide-3-kinase-protein kinase B/Akt [PI3K-PKB/Akt], Janus kinase/signal transducers and activators of transcription [JAK/STAT], and mitogen-activated protein kinase [MAPK] pathways), the reduction of proapoptotic protein expression, the increase in cell migration and invasion, and the enhancement in metastasis are addressed. Cigarette smoking is one of the major causes of carcinogenesis. The incidence of breast cancer is increasing worldwide, making it the most common type of cancer among women. The etiology of breast cancer is multifactorial and cigarette smoking is one of the risk factors that has recently been shown to be associated with breast cancer. The relationship between cigarette smoking and breast cancer is due to one of the important components of cigarette smoke, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which is a representative carcinogen of N-nitrosamines that has gained focus in breast cancer carcinogenesis. The purpose of this review is to investigate the relationship between breast cancer and chronic periodontal disease changes that can occur at the oral level, including alterations of the oral microbiome, and pathological conditions among postmenopausal female smokers. Chronic periodontal disease and tooth loss were highly prevalent in postmenopausal breast cancer survivors. Based on this traditional review, the importance of dentists is clear in proposing to patients with breast cancer appropriate therapies and dedicated prevention sessions.