New study links oral hygiene to pancreatic cancer risk

Researchers found distinct differences in the oral microbiome between those who developed the cancer and those who did not. (Photo: Freepik)

By Charity Kilei
Thursday, September 25, 2025

The study highlights the urgent need for earlier diagnosis, better access to treatment, and public awareness of symptoms to improve survival rates in Kenya.

A recent study published in Jama Oncology has uncovered a potential link between oral hygiene and the risk of developing pancreatic cancer, one of the deadliest and hardest-to-detect cancers.

Pancreatic cancer affects the pancreas, an organ behind the stomach that aids digestion and blood sugar regulation.

It occurs when pancreatic cells grow uncontrollably and is often detected late due to a lack of early symptoms, making it highly lethal, according to the US Centres for Disease Control and Prevention (CDC).

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The research analysed saliva samples from more than 122,000 adults for nearly nine years, during which 445 developed pancreatic cancer.

By analysing saliva samples, researchers found distinct differences in the oral microbiome, the bacteria and fungi in the mouth, between those who developed the cancer and those who did not.

Notably, higher levels of certain harmful bacteria linked to gum disease, Porphyromonas gingivalis, Eubacterium nodatum, and Parvimonas micra, were associated with a significantly increased risk. An elevated presence of Candida fungi was also observed.

Scientists suggest these microbes may enter the pancreas through the bloodstream or digestive tract, where they could trigger inflammation or other changes that contribute to cancer development.

To quantify the risk, the researchers developed a Microbial Risk Score (MRS), based on the presence and levels of 27 different microbes. The results were striking: each increase in the score was linked to more than a threefold rise in pancreatic cancer odds.

CDC notes pancreatic cancer as one of the most serious cancers because it is often detected at a late stage, when treatment is more challenging. Early pancreatic cancer typically causes no symptoms, making a timely diagnosis difficult.

As the disease progresses, warning signs may emerge, including yellowing of the skin and eyes (jaundice), dark urine, and pale or greasy stools. Many patients experience upper abdominal or back pain, unexplained weight loss, loss of appetite, nausea, and extreme fatigue. A sudden diagnosis of diabetes or worsening of existing diabetes can also be an indicator.

Experts have identified several risk factors that increase the likelihood of developing pancreatic cancer. These include smoking, long-term diabetes, obesity, and chronic pancreatitis (persistent inflammation of the pancreas). A family history of pancreatic cancer or certain genetic conditions also raises risk.

Lifestyle factors such as diets high in red or processed meats, physical inactivity, and heavy alcohol consumption contribute as well. The disease is more common in those over 60 and tends to affect men slightly more than women.

Because pancreatic cancer can develop silently, recognising symptoms and understanding risk factors is crucial. Early detection improves outcomes. Preventive measures include avoiding tobacco, maintaining a healthy diet and weight, and regular medical check-ups.

In Kenya, a study at Kenyatta National Hospital (KNH) involving 242 patients found that most were diagnosed late, with over half at stage IV. Early-stage diagnosis was rare, limiting treatment success.

Common symptoms included abdominal pain, jaundice, weight loss, and appetite loss, often persisting for months before treatment. Only 7 per cent had curative surgery, with many receiving only supportive care. Median survival was three months, with one-year survival at 32 per cent, though those receiving surgery or chemotherapy had better outcomes.

Pancreatic cancer accounted for about 1 per cent of all Kenyan cancer cases, with deaths rising sharply from 188 in 1990 to 667 in 2017.

Globally, the World Health Organisation estimates 510,000 new cases and over 466,000 deaths in 2022, ranking it seventh in cancer mortality. The five-year survival rate is under 10 per cent, highlighting the need for earlier detection and better treatment.

Early symptom awareness and risk reduction, such as avoiding tobacco, eating healthily, maintaining weight, and regular medical check-ups, are crucial for improving outcomes.