Study: Gallstones May Come Before Pancreatic Cancer Diagnosis

A recent epidemiological study from researchers at Boston Medical Center showed that people diagnosed with pancreatic cancer were six times more likely to have been treated for gallstone disease the year before their cancer diagnosis.

The researchers now wonder if the link could lead to a way to detect pancreatic cancer earlier when it’s at a more treatable stage. Finding and treating the cancer sooner could improve outcomes for the estimated 62,210 people who are diagnosed with it each year.

The early findings from the study were presented in May during the 2022 Digestive Disease Week conference in San Diego.

What the Researchers Found

The researchers used data from the SEER-Medicare database—which links cancer data from the National Cancer Institute with Medicare data from the Centers for Medicare and Medicaid Services—from 2008 to 2015. They identified patients who were diagnosed with pancreatic ductal adenocarcinoma (PDAC) who also had gallstone disease the year before they got a cancer diagnosis.

Of the 18,700 people with PDAC identified, 4.7% also had gallstone disease. Of those people, 1.6% had their gallbladders removed.

The researchers also noted that the people diagnosed with PDAC who also had a history of gallstone disease were diagnosed with cancer at an early stage and underwent surgery at a higher rate than the people with PDAC who did not have gallstone disease.

Limitations of the Study

Walter Park, MD, associate professor of gastroenterology and hepatology at Stanford Hospital and Clinics told Verywell that “while this information is still premature and details of the study are unknown, there does seem to be a pattern—but not necessarily a causality.”

Park—who was not involved in the study—also explained that “people with gallbladder disease are already in the healthcare system being monitored,” which could explain an earlier diagnosis.

According to Park, when this occurs in research, it’s called detection bias.

While the results of the study do not suggest that gallstones lead to pancreatic cancer, there are a variety of reasons that people with a history of gallstone disease need close follow-up from their healthcare providers. Keeping an eye on them for a potential cancer diagnosis down the road could be another one.

In a press release for the research, Marianna Papageorge, MD, a research fellow at Boston Medical Center and lead researcher on the study, pointed out that “pancreatic cancer is very rare, and many people have gallstone disease.”

“[The study’s findings] should motivate us to ensure that patients have good follow-up care, that they’re seeing a primary care physician more regularly, and following up with their surgeon if they had their gallbladder removed,” Papageorge said, adding that continuation of care will help lead to an earlier cancer diagnosis.

Gallstones and the Pancreas

Gallstones, which are common and affect approximately 15% of the population, are tiny, hard (almost rock-like) substances made of cholesterol and bilirubin that form in the gallbladder.

The little “stones” can be a big problem if they block the bile duct, which can cause severe pain (often in the upper ride part of your abdomen). Gallstones are typically treated by removing the gallbladder.

The pancreas is a gland behind the stomach. It makes insulin and enzymes that help your small intestine digest food. The pancreas and the gallbladder work together to make and store the chemicals your body needs to break down food so it can be absorbed by the small intestine.

Gallstone disease can hurt the pancreas by blocking the pancreatic duct. This lead to inflammation—a condition known as gallstone pancreatitis.

A person with a case of acute pancreatitis may have to be in the hospital to get fluids and antibiotics. If they can’t eat, they may need to have a tube placed for nutrition.

If a person keeps getting “attacks” of pancreatitis, it usually means the condition has become chronic. Sometimes, changing their diet can help but they may need surgery if it’s severe.

Why We Need Better Pancreatic Cancer Screening

Pancreatic cancer is the third leading cause of cancer death in the United States behind lung and colon cancer. It’s a type of cancer that’s hard to diagnose early because the symptoms often do not appear until the tumor has grown or spread to other parts of the body.

According to the American Cancer Society, about half of pancreatic cancers have metastasized at the time of diagnosis, leaving people with fewer treatment options.

When a person with pancreatic does have symptoms, they may include:

• Jaundice (yellowing of the eyes and skin)
• Dark urine
• Light-colored or greasy stools
• Losing weight without trying
• Poor appetite
• Blood clots
• An enlarged gallbladder or liver
• Nausea and vomiting 
• Diabetes

Current Pancreatic Cancer Screening and Diagnosis

The currently used diagnostic tests for pancreatic cancer do not reduce a person’s risk of dying from the disease. Therefore, there isn’t a general population screening for pancreatic cancer like there is for other types of cancer.

Screening for pancreatic cancer is only recommended for high-risk people who are over the age of 50 and have risk factors including:

• First degree relatives with pancreatic cancer 
• Peutz–Jeghers syndrome
• Hereditary pancreatitis 
• People with CDKN2A, BRCA1, BRCA2, PALB2, and ATM gene mutations

Pancreatic cancer screening usually starts with a physical and detailed family history. If signs and symptoms are present, pancreatic cancer can be diagnosed using imaging tests such as:

• Computed tomography (CT) scan
• Magnetic resonance imaging (MRI)
• Ultrasound
• Cholangiopancreatography (imaging of the pancreatic and bile ducts)
• Positron emission tomography (PET) scan

Can Pancreatic Cancer Be Prevented?

There’s no one way to prevent pancreatic cancer. However, if your age, family history, and genetics put you at a higher risk for pancreatic cancer, there are steps you can take to help lower your risk, including:

• Do not smoke or quit if you do
• Limit your alcohol consumption
• Eat a balanced diet and limit red meat, processed food, and added sugar
• Maintain a weight that’s healthy for you
• Get regular exercise

More Research Needed

While experts are waiting for the new study to be fully published, the initial results could spur more research into the pattern of gallstone disease and a later pancreatic cancer diagnosis.

While the new study provided some insight into how many people with pancreatic cancer also had gallstone disease, Park said he would like to know the percentage of people with gallstone disease that develop pancreatic cancer.