'Is It Really This Much?'... Untreated Tooth Loss Raises Cancer Risk by 18% in Adults Over 50

Untreated Tooth Loss Raises Cancer Risk by 18% in Adults Over 50
Oral Diseases Linked to Higher Incidence and Mortality of Major Cancers

Research has found that having oral diseases such as dental caries or gingivitis increases both the risk of developing cancer and the mortality rate from cancer. In particular, among individuals over 50, leaving a missing tooth untreated was found to increase the risk of cancer by 18%.

In individuals over 50, leaving a missing tooth untreated was found to increase the risk of cancer by 18%. Photo by Getty Images

On July 16, Professor Kim Gyehyung of Seoul National University Hospital’s Public Healthcare Center and Dr. Lee Seungyeon of Seoul Boramae Hospital’s Public Sector announced these findings after tracking and observing health data from approximately 3.8 million Korean adults. The results were published in a recent issue of the international journal Science Progress.

The research team analyzed the medical records from the National Health Insurance Service and tracked 3,845,280 adults who underwent oral health screenings in 2009 until 2019. Oral diseases were classified into three categories: dental caries, gingivitis (inflammation of the gums), and tooth loss (missing teeth). The team then analyzed cancer incidence and mortality according to the presence of each oral disease.

The analysis revealed a total of 181,754 cancer cases, with a higher incidence among those with oral diseases. Specifically, individuals with tooth loss experienced a 13% higher incidence of colorectal cancer, a 9% higher incidence of liver cancer, an 8% higher incidence of stomach cancer, and a 4% higher incidence of lung cancer. In those with gingivitis, liver cancer incidence was 8% higher and colorectal cancer was 7% higher.

There were also significant differences in cancer mortality rates. Over the 10-year period, there were 37,135 cancer-related deaths, with a higher risk of cancer death among those with oral diseases. More specifically, individuals with tooth loss had a 24% higher mortality rate from prostate cancer, a 21% higher rate from stomach cancer, a 16% higher rate from liver cancer, a 14% higher rate from colorectal cancer, and an 8% higher rate from lung cancer. Gingivitis was also found to increase liver cancer mortality by 11%.

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This trend was even more pronounced among adults aged 50 and older. In this group, tooth loss was found to increase the overall risk of developing cancer by 18%. Higher incidence rates were observed for major gastrointestinal cancers, including stomach, colorectal, and liver cancer, and this pattern was seen even among those with no history of smoking. These findings suggest that oral diseases may serve as independent risk factors for cancer, beyond lifestyle factors.

Professor Kim explained, "Oral diseases do not only affect dental health; they can trigger systemic inflammatory responses through chronic inflammation, and this process may be involved in the development and progression of cancer." He emphasized, "Regular oral checkups, hygiene management, and dental treatment could become new strategies for cancer prevention."