A person’s teeth may hold a surprising clue to how long they survive after pancreatic cancer surgery.
In a new study, patients with at least 21 natural teeth survived nearly two years longer, on average, than those with fewer teeth. Researchers suspect that the mouth may preserve signs of inflammation, nutrition, frailty, and other health pressures that accumulate throughout life.
Scientists at Hiroshima University investigated whether oral health could help predict long-term outcomes in people treated surgically for pancreatic ductal adenocarcinoma (PDAC), an aggressive form of pancreatic cancer. Previous research has connected poor oral health with outcomes in colorectal and esophageal cancers, as well as complications after pancreatic cancer surgery.
The new study shifted the focus from short-term complications to survival after resection, the surgical removal of all or part of an organ. The findings were published in the Journal of Hepato-Biliary-Pancreatic Sciences on April 23, 2026.
How Oral Health Could Affect Cancer Survival
“Pancreatic cancer remains one of the deadliest malignancies worldwide, and even after curative resection, prognosis is often poor,” said Kenichiro Uemura, associate professor at Hiroshima University’s Graduate School of Biomedical and Health Sciences and corresponding author of the study. “Recently, several high-impact studies have suggested that periodontal pathogens such as Porphyromonas gingivalis may contribute to pancreatic carcinogenesis and tumor progression. However, it has remained unclear whether oral health itself influences postoperative survival outcomes in patients with pancreatic cancer.”
The researchers examined 339 consecutive patients who underwent radical pancreatectomy (surgery where all or part of the pancreas is removed, occasionally along with parts of other organs) at Hiroshima University Hospital between 2014 and 2022.
Before surgery, every patient received a dental examination. The team recorded how many natural teeth remained and evaluated posterior occlusion (contact between upper and lower teeth), which indicates whether the premolars and molars can meet during chewing.
More Teeth Linked to Longer Survival
The difference in survival was substantial. Patients with 21 or more natural teeth had a median overall survival of 60.7 months, or just over five years. Among those with 20 or fewer teeth, median survival fell to 39.1 months, or slightly more than three years.
Tooth count remained associated with survival even after the researchers adjusted for major factors that could affect the results, including tumor stage, lymph node metastasis, surgical margins, chemotherapy, and nutritional status.
“One striking finding was the large survival difference between the groups: patients with more natural teeth survived nearly two years longer than those with fewer teeth,” Uemura said.
“Another surprising finding was that chewing function itself, evaluated by posterior teeth occlusion, was not independently associated with survival. This suggests that tooth loss may represent more than oral function alone. Instead, it may reflect lifelong chronic inflammation, frailty, nutritional condition, lifestyle factors, and overall systemic vulnerability accumulated over decades. A simple way to express this concept is, ‘The mouth may reflect the body’s long-term resilience.’”
Tooth Loss as a Lifelong Health Signal
The contrast between tooth count and chewing function may be important. If difficulty chewing were the main explanation, posterior occlusion would also be expected to predict survival. Because it did not, the researchers argue that missing teeth may instead serve as a visible record of long-term health.
Tooth loss can arise from several overlapping influences, including periodontal disease, smoking, diet, access to dental care, chronic illness, and aging. Many of these factors may also affect how well the body tolerates major surgery, chemotherapy, inflammation, and the physical strain of cancer. The study did not establish which of these possible pathways explains the survival difference.
The study was conducted at one hospital and involved patients of Japanese ethnicity, limiting how broadly the results can currently be applied. Larger studies involving multiple hospitals and more diverse populations will be needed to confirm the association. Researchers also want to investigate whether oral bacteria and chronic inflammation play a direct role in pancreatic cancer progression.
“Our ultimate goal is to establish a new perspective in pancreatic cancer care: prognosis may depend not only on tumor biology but also on the patient’s long-term systemic condition and oral health environment,” Uemura concluded. “We hope oral health assessment may eventually become part of personalized risk stratification and perioperative management for pancreatic cancer patients.”
Reference: “Independent Prognostic Value of Natural Tooth Count Versus Posterior Teeth Occlusion in Resected Pancreatic Cancer” by Kaoru Seo, Kenichiro Uemura, Kenjiro Okada, Hiromi Nishi, Tatsuaki Sumiyoshi, Ryuta Shintakuya, Yoshiaki Murakami, Hiroyuki Kawaguchi and Shinya Takahashi, 23 April 2026, Journal of Hepato-Biliary-Pancreatic Sciences.
DOI: 10.1002/jhbp.70113
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