Breast Cancer, Poor Oral Health, and Chronic Gum Inflammation: Recognizing the Connections

Breast cancer is the most common malignancy among women worldwide, while poor oral health, particularly chronic gum inflammation (periodontitis), is a widespread condition with significant implications for systemic health. Emerging research suggests a potential connection between poor oral hygiene, chronic gum inflammation, and breast cancer, further emphasizing the systemic consequences of oral health. This article reviews the mechanisms and evidence that support the relationship between poor oral health, chronic gum inflammation, and breast cancer.

Oral Health and Systemic Disease

Oral health plays a crucial role in overall systemic health. Poor oral hygiene, which leads to conditions like periodontitis and gingivitis, is characterized by bacterial infections that trigger chronic inflammation. This inflammation can become systemic, contributing to various chronic conditions, such as cardiovascular diseases, diabetes, and cancer, including breast cancer. Inflammation, in particular, is a key factor in the development and progression of many chronic diseases. Persistent inflammation caused by periodontal disease may act as a precursor to cancer through the production of inflammatory mediators and oxidative stress.

Inflammation and Breast Cancer: A Biological Mechanism

Chronic inflammation is now recognized as a significant driver of cancer development. Periodontitis, a chronic inflammatory disease, results in a prolonged immune response to bacterial infection in the gums. During this process, pro-inflammatory cytokines such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) are released, contributing to systemic inflammation. This state of inflammation not only damages tissues locally but also has systemic effects that may influence the development of malignancies, such as breast cancer.

A key mechanism by which poor oral hygiene and periodontitis may contribute to breast cancer is the systemic dissemination of oral pathogens. Bacteria such as Porphyromonas gingivalis and Fusobacterium nucleatum, common in periodontal disease, can spread beyond the oral cavity to distant tissues, including the breast. Once present in other organs, these bacteria can modify the local immune environment, fostering conditions conducive to cancer development.

Microbial Influence on Cancer Development

The human microbiome, including the oral microbiome, is increasingly recognized as an essential factor in health and disease. Dysbiosis, or the disruption of the average microbial balance, has been linked to various cancers, including breast cancer. Poor oral hygiene can lead to an imbalanced oral microbiome, allowing pathogenic bacteria to proliferate and potentially disseminate to other parts of the body. Studies have identified oral pathogens, such as *F. nucleatum*, in breast cancer tissues, suggesting a direct link between oral bacteria and tumor development.

*F. nucleatum* has been implicated in promoting tumor progression by inducing an inflammatory tumor microenvironment and modulating the immune response to favor cancer cell survival. Additionally, *P. gingivalis* has been associated with chronic inflammation, which can lead to the disruption of cellular functions and genetic mutations that contribute to cancer development. The presence of these pathogens in breast tissue underscores the potential role of oral bacteria in cancer metastasis and progression.

Epidemiological Evidence Linking Periodontal Disease and Breast Cancer

Several epidemiological studies have explored the association between periodontal disease and breast cancer risk. A notable study by Freudenheim et al. (2016) examined over 70,000 postmenopausal women and found that those with a history of periodontal disease had a 14% increased risk of developing breast cancer compared to those without periodontal disease. This study suggests that chronic gum inflammation may contribute to breast cancer risk, especially in individuals with other risk factors, such as smoking.

Further supporting this association, Sfreddo et al. (2017) conducted a meta-analysis of multiple observational studies, which confirmed a positive link between periodontal disease and an increased risk of breast cancer. While more research is necessary to establish causality, the consistency of these findings suggests a significant connection between chronic gum inflammation and breast cancer risk.

Inflammatory and Immune Responses in Breast Cancer

The immune system plays a crucial role in protecting against and promoting cancer. Chronic gum inflammation can weaken the immune system’s ability to detect and destroy cancer cells. In periodontal disease, immune cells such as macrophages and T-cells are persistently activated, creating a pro-inflammatory environment that may support tumor growth. This environment can suppress the body’s anti-tumor immunity, allowing cancer cells to evade immune surveillance.

Moreover, periodontal disease increases oxidative stress, an imbalance between reactive oxygen species (ROS) production and the body’s ability to neutralize them. Elevated levels of ROS can cause DNA damage, which can lead to the mutations that drive cancer development. In breast tissue, oxidative stress resulting from chronic inflammation may enhance the likelihood of malignant transformations and contribute to cancer progression.

Implications for Breast Cancer Survivors and Oral Health Management

Oral health remains critical for breast cancer survivors, as cancer treatments, including chemotherapy and radiation, can exacerbate pre-existing oral health conditions. Treatments can reduce salivary flow, alter the oral microbiome, and cause mucositis, all of which can contribute to periodontal disease and poor oral health. These complications can negatively affect a patient's quality of life and may even influence breast cancer prognosis. Regular dental care and proper oral hygiene are essential for minimizing the risk of these complications and improving overall outcomes for breast cancer survivors.

Recommendations for Prevention and Healthcare Integration

Given the potential relationship between chronic gum inflammation and breast cancer, maintaining good oral hygiene is an essential preventive strategy. Regular brushing, flossing, and dental check-ups are necessary to reduce the risk of periodontal disease and its associated inflammatory effects. Women with a history of periodontal disease may also benefit from more frequent cancer screenings, especially if they have additional risk factors for breast cancer.

Public health initiatives should aim to raise awareness of the systemic health consequences of poor oral hygiene, encouraging comprehensive healthcare approaches that integrate oral and systemic health. By improving access to dental care and promoting oral health, healthcare systems can address a significant risk factor in breast cancer prevention.

Conclusion

The connection between breast cancer and poor oral health, particularly chronic gum inflammation, is supported by growing evidence. Mechanisms involving systemic inflammation, microbial translocation, and immune system alterations appear to play critical roles in this relationship. While more research is needed to establish a definitive causal link, the existing data suggest that maintaining good oral health may reduce the risk of breast cancer. Integrating oral hygiene into cancer prevention strategies and public health policies could provide a significant benefit in reducing the burden of both breast cancer and other chronic diseases linked to inflammation.

AAOSH Resources

The AAOSH Core Curriculum areas, Periodontal and Biofilm Diseases of the Mouth and Cancer and Autoimmune Disorders are designed to equip dental professionals with the tools and knowledge needed to thrive in the ever-evolving field of oral systemic health. Our comprehensive curriculum emphasizes integrating oral and systemic care, offering practical strategies for improving patient outcomes and enhancing practice efficiency. With a focus on continuous improvement and professional growth, this curriculum is essential for anyone looking to elevate their practice and make a lasting impact on their patients' lives.

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Asymptomatic Oral Infections Cause Most Heart Attacks and Breast Cancers

Presented by: Thomas Levy, MD, JD
Original Publication Date: November 09, 2018

Course Description:

Join us for a captivating journey through the intricate world of health and disease in this course, featuring Dr. Thomas Levy's presentation from the 2018 Scientific Sessions. Here, you will explore the pivotal role of oxidative stress as a foundational factor in many chronic diseases, enhancing your understanding of this critical concept. Delve into the principles of Redox physiology, unraveling the intricacies of oxidative-reduction reactions within the human body. With a comprehensive grasp of the primary sources and contributors to increased oxidative stress, you will analyze the profound impact of latent oral infections on the development and progression of chronic illnesses. But that's not all; this course equips you with practical recommendations for the prevention and treatment of chronic diseases, with a specific focus on mitigating oxidative stress. Discover a wealth of knowledge to transform your approach to healthcare and well-being.

Learning Objectives:

• Understand the concept that increased oxidative stress can be a foundational cause for various chronic diseases.
• Comprehend the principles of Redox physiology, which relate to oxidative-reduction reactions in the body.
• Understand the primary sources and factors contributing to increased oxidative stress.
• Analyze the substantial impact of latent oral infections on the development and progression of chronic diseases.
• Apply practical recommendations for both the prevention and treatment of chronic diseases with a focus on reducing oxidative stress.

Dr. Thomas Levy is a distinguished medical professional and an influential figure in the field of integrative and preventive medicine. Renowned for his extensive research and expertise in the role of oxidative stress in chronic diseases, Dr. Levy's work has made a significant impact on the healthcare landscape. He is a respected author, lecturer, and clinician, and his passion for advancing health and wellness has been instrumental in improving the lives of many. Dr. Levy's dedication to uncovering the intricacies of health and disease continues to shape the field of medicine and inspire countless individuals on their journeys to well-being.

The Microbiome, Inflammation, and Cancer

Presented by: Mark Rosenberg, MD
Original Presentation Date: September 15, 2017

• Analyze the correlation between dysbiosis, compromised immune function, and their association with cancer development, demonstrating an understanding of the underlying biological mechanisms.
• Evaluate the empirical evidence highlighting the relationship between periodontal disease and various cancer types, fostering familiarity with pertinent data to assess their interconnectedness within healthcare contexts.
• Assess the available data concerning the restoration of wellness by addressing and repairing the microbiome, demonstrating an understanding of how microbiome repair contributes to overall health improvement.
• Critically analyze the existing research on the impact of fasting on immune function, demonstrating familiarity with the data and its implications for enhancing immune response and overall health.

Speaker Bio:

Dr. Mark Rosenberg, initially trained in emergency medicine, underwent a transformative experience approximately 14 years ago while practicing in the emergency department when he diagnosed his mother with metastatic lung cancer—her passing nine months later prompted Dr. Rosenberg to delve into the study of tumor metabolism. This journey led him to assume the role of program director for the inaugural integrative cancer fellowship. Transitioning into the domain of cancer science, Dr. Rosenberg established a pharmaceutical company focused on pioneering drugs tailored to target cancer stem cells, advancing the forefront of cancer treatment.

References (In order of appearance): 

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Scannapieco, F.A., Bush, R.B., & Paju, S. (2003). Associations between periodontal disease and risk for atherosclerosis, cardiovascular disease, and stroke. A systematic review. Annals of Periodontology, 8(1), 38-53. doi:10.1902/annals.2003.8.1.38

Fitzpatrick, S.G., & Katz, J. (2010). The association between periodontal disease and cancer: a review of the literature. Journal of Dentistry, 38(2), 83-95. doi:10.1016/j.jdent.2009.10.007

Olson, S.H., et al. (2019). Periodontal disease, tooth loss, and cancer risk in postmenopausal women. Cancer Causes & Control, 30(4), 417-424. https://doi.org/10.1093/epirev/mxx006 

Freudenheim, J.L., et al. (2016). Periodontal disease and breast cancer: prospective cohort study of postmenopausal women. Cancer Epidemiology, Biomarkers & Prevention, 25(1), 43-50. doi:10.1158/1055-9965.EPI-15-0750

Sfreddo, C.S., et al. (2017). Association between periodontal disease and breast cancer: a systematic review and meta-analysis. Journal of Clinical Periodontology, 44(4), 446-457. https://doi.org/10.1158/1940-6207.CAPR-20-0018 

Hong, C.H., & Napenas, J.J. (2012). Oral health complications of cancer therapies: radiation, chemotherapy, and hematopoietic stem cell transplantation. Journal of Clinical Oncology, 28(10), 4858-4865. doi:10.3322/caac.21157

Warnakulasuriya, S. (2010). Global epidemiology of oral and oropharyngeal cancer. Oral Oncology, 45(4), 309-316. doi:10.1016/j.oraloncology.2008.06.002