Oral health is known to be linked to overall health, and research has shown relationships with a variety of diseases. Impaired oral health has been linked to prognosis in colorectal cancer and esophageal cancer. Previous studies have also shown an association between oral health and postoperative complications in pancreatic ductal adenocarcinoma (PDAC), one of the more lethal forms of cancer.

Researchers at Hiroshima University examined the prognostic impact of oral health in patients undergoing resection, the surgical removal of all or part of an organ, as treatment for PDAC.  They specifically evaluated the association between oral health and long-term survival outcomes.

Their findings were published in the Journal of Hepato-Biliary-Pancreatic Sciences on April 23, 2026.

“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 study comprised of 339 consecutive patients who underwent radical pancreatectomy (surgery where all or part of the pancreas is removed, occasionally along with parts of other organs) between 2014 and 2022 at the Department of Surgery, Hiroshima University Hospital. All patients underwent a pre-operative dental examination to evaluate dental health based on two major criteria: number of teeth and status of occlusion (contact between upper and lower teeth) of the pre-molar and molars.

The researchers showed that patients with fewer natural teeth had significantly worse survival after pancreatic cancer surgery. Patients with 21 or more natural teeth had a median overall survival of 60.7 months, whereas those with 20 or fewer teeth had a median survival of only 39.1 months. Importantly, this association remained significant even after adjusting for established prognostic factors such as 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 says. “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.’”

As this study was a single-center study comprising patients of Japanese ethnicity, the next step is to validate these findings through larger multicenter and international studies and to further investigate the biological relationship between oral bacteria, chronic inflammation, and 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 concludes. “We hope oral health assessment may eventually become part of personalized risk stratification and perioperative management for pancreatic cancer patients.”

Kaoru Seo, Kenichiro Uemura, Kenjiro Okada, Tatsuaki Sumiyoshi, Ryuta Shintakuya and Shinya Takahashi at Hiroshima University; Hiromi Nishi and Hiroyuki Kawaguchi at Hiroshima University Hospital; and; Yoshiaki Murakami at Hiroshima Memorial Hospital co-authored the study. Kaoru Seo was first author of the study; Kenichiro Uemura was Principal Investigator (PI).

• Journal: Journal of Hepato-Biliary-Pancreatic Sciences
• Title: Independent Prognostic Value of Natural Tooth Count Versus Posterior Teeth Occlusion in Resected Pancreatic Cancer
• Authors: Kaoru Seo, Kenichiro Uemura, Kenjiro Okada, Hiromi Nishi, Tatsuaki Sumiyoshi, Ryuta Shintakuya, Yoshiaki Murakami, Hiroyuki Kawaguchi, Shinya Takahashi
• DOI: 10.1002/jhbp.70113
• Date: April 23, 2026