Once viewed as peripheral to broader medical concerns, oral health is now being recognised as a critical determinant in systemic diseases including cancer. A growing body of research from India and globally highlights how chronic periodontal conditions, oral pathogens and poor access to dental care significantly influence the risk, progression and outcomes of cancers, particularly in the oral cavity, digestive tract and pancreas.
Persistent burden and patchy surveillance
Globally, an estimated 3.5 billion people are affected by oral diseases. While many countries have seen improved oral health indicators in recent decades, India has not kept pace. Oral disorders remain one of the leading causes of disability in the country, affecting individuals across age groups and socioeconomic strata.
India’s last national oral health survey was conducted in 2007–08. Since then, there has been no updated, nationwide data, leading to significant blind spots in planning and policy. The Draft National Oral Health Policy (2021) outlines the need for baseline data by 2025 and proposes a 15% reduction in mortality and morbidity due to orofacial diseases by 2030. However, without reliable surveillance systems or integration with broader public health efforts, these goals remain aspirational.
Also, the World Health Organization has recognised oral health as a vital component of non-communicable disease (NCD) prevention, calling for stronger integration between dental and general medical care.
Cancer risk and the oral cavity
A recent study titled “Oral Health and its Expanding Role in Systemic Disease, Cancer Outcomes, and Public Health”, published in The Lancet, by Abhishek Shankar, assistant professor and Vaibhav Saini, scientist from the Department of Radiation Oncology at AIIMS, Delhi, underlines how oral hygiene may serve as a modifiable risk factor in cancer. Drawing on data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium, the authors report that good oral hygiene is associated with a modest reduction in head and neck cancer risk.
Observational data further suggest a possible association between periodontal disease, root canal infections, and increased risk of pancreatic and upper gastrointestinal cancers. “The evidence certainly points towards considering oral health as an integral part of cancer care,” the study investigators note, emphasising the need to embed dental care within oncology pathways.
Oral pathogens are also implicated in cancer biology. Porphyromonas gingivalis and Prevotella intermedia, commonly found in chronic gum disease, are increasingly understood to influence tumour development. “P. gingivalis evades immune surveillance, invades host tissues, and promotes cancer proliferation,” write Dr. Shankar and Dr. Saini. “P. intermedia, on the other hand, alters the tumour microenvironment and down regulates tumour suppressors.”
Syed Ismail Nawab John, clinical lead at MGM Cancer Institute, Chennai, adds that bacteria such as Fusobacterium nucleatum have been linked with colorectal cancer by altering local immune responses. “Bacterial byproducts such as butyrate can damage DNA and disrupt cellular repair. In a large cohort study published in Gut in 2018, individuals with severe periodontal disease had a 20–50% higher risk of developing pancreatic and colorectal cancers.”
Vijay Pillai, senior consultant and chief of head and neck surgical oncology at Narayana Health City, Bengaluru, notes that oral dysbiosis — an imbalance or disruption in the community of microorganisms (microbiome) that naturally inhabit the oral cavity, especially involving Fusobacterium and Bacteroides may contribute to a pro-inflammatory state that favours tumour progression. “Early detection of potentially malignant lesions can significantly downstage disease and improve outcomes,” he says.
Impact on cancer treatment
Oral health also has implications for cancer therapy. Radiotherapy for head and neck cancers disrupts the oral microbiome, often suppressing protective bacteria and allowing harmful strains to thrive. “Patients with periodontal disease who undergo radiotherapy are particularly susceptible to complications such as impaired bone healing,” say the AIIMS researchers. Retention of natural teeth and frequent dental consultations are linked to better survival in head and neck cancer patients.
In contrast to Western countries, where oral health data are routinely collected through registries, India and much of Southeast Asia lack comprehensive oral health surveillance. “Region-specific data is essential for relevant decision-making,” stress Dr. Shankar and Dr. Saini. “Existing registries and collaborations are underutilised unless integrated into national cancer care frameworks.”
Dr. John concurs, calling the absence of surveillance a major public health downside. “Integrating dental metrics into cancer registries would be a strategic step forward.”
Towards integrated prevention
Evidence suggests that community-level interventions such as school toothbrushing programmes, fluoride education and low-cost point-of-care diagnostics like aMMP-8 testing can reduce systemic inflammation and potentially lower cancer risk. A study in the Journal of Clinical Periodontology showed that professional periodontal treatment led to decreased levels of CRP and IL-6, both biomarkers associated with cancer progression.
“Oral health should no longer be siloed,” says Dr. John. Experts are urging the inclusion of oral health in national cancer control plans, school health programmes, and tobacco cessation curricula. Policy changes such as mandatory front-of-pack nutrition labels and bans on cartoon characters in junk food advertising are also being advocated to reduce early-life exposure to oral and systemic health risks.
Community-based dental interventions, particularly for low-income communities, may help reduce the prevalence of periodontal disease and the systemic burden of oral pathogens. By reducing inflammatory markers and enhancing early detection, these efforts could play a role not only in improving oral hygiene but in reducing the broader burden of cancer and other non-communicable diseases.
Published – July 28, 2025 04:43 pm IST
