Are Pancreatic Cysts Dangerous? Do They Cause Pancreatic Cancer?

This article was reviewed by our Baystate Health team to ensure medical accuracy.

John W. Miller, MD John W. Miller, MD View Profile
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The pancreas is one of those organs that people don’t think about until there’s an issue. The most common potential pancreatic issue is a cyst. According to Dr. John Miller, a gastroenterologist and interventional endoscopist at Baystate Gastroenterology in Springfield, “Any time the pancreas gets mentioned, people’s anxiety instantly goes from zero to 100, and their thoughts immediately jump to cancer. Which is unfortunate as in most cases, cysts are rarely life-threatening, and rarely ever progress into cancer, and are certainly not deserving of the concern, or even panic, that some patients experience.”

What is a Pancreatic Cyst?

Before we dive into cysts, let’s take a second to talk about the pancreas. A small yet important organ, the roughly six-inch pancreas is located in the center of the body where it produces enzymes and hormones that help with digestion and work to control blood sugar levels.

Like any other part of the body, the pancreas can develop cysts, which are balloon-like structures that fill with mucus or fluid. Roughly 3 to 15% of people have pancreatic cysts. That percentage jumps to nearly 40% in people aged 70 and over. In many, many cases, these non-symptomatic cysts are only discovered when an individual has imaging (an MRI or CT scan) for an unrelated physical issue that is causing symptoms.

What Miller emphasizes to the people who come to him after a cyst is discovered is this: “Only one-quarter of one percent of pancreatic cysts found through ‘unrelated’ imaging is cancerous. And of the huge majority that aren’t cancerous at the time of discovery, less than one-quarter of one percent of those will develop into cancer in the year that follows.”

Even in the case of cysts that are large enough to cause symptoms—such as recurrent pancreatitis (inflammation of the pancreas requiring admission to the hospital), or yellowing of the skin or eyes—it is rare that they are cancerous.

Different Types of Pancreatic Cysts

While there are five different types of pancreatic cysts, Miller likes to break them down into two camps: those that have no potential for cancer and those that do.

“The two kinds of cysts that pose no risk for cancer are pseudocysts and serous cystadenomas,” he explains. “Pseudocysts are commonly found in patients who have pancreatitis. Pancreatitis-related inflammation can lead to scarring, and we’ll often see cysts form on or near the scarred area.”

Serous cystadenomas, he notes, are far less common and rarely cause symptoms, making treatment unnecessary.

As for the types of cysts that do have the potential to develop into cancer, Miller says there are three:

  • IPMN (side branch)
  • IPMN (main duct or mixed type)
  • Mucinous cystic neoplasm (MCN)

IPMN (intraductal papillary mucinous neoplasms) cysts are the most common type of cyst and do carry a small risk of progression to pancreas cancer. These develop in the ducts, or tiny canals, that serve as the plumbing system of the pancreas. Exactly where a cyst develops determines whether it’s a side branch or a main duct/mixed type. Side branch cysts are small and do not connect to the main duct of the pancreas; these have a very low risk of progression to pancreas cancer.

These types of cysts produce a lot of mucus. In some cases, the mucus produced can block your pancreatic ducts which can lead to pancreatitis. The mucus also tends to make the pancreatic main duct large on imaging. “When this occurs,” says Miller, “it serves as a clue to us that we need to examine these cases carefully. This change is a high-risk finding and warrants close evaluation.”

Generally less concerning than IPMNs are mucinous cystic neoplasms. While they start out as benign, they do tend to progress towards cancer. Occurring on the tail of the pancreas, MCNs are easy to detect and recognize through imaging, and relatively easy to remove via surgery with an excellent prognosis for no recurrence of cancer.

How Are Pancreatic Cysts Diagnosed?

Pancreatic cysts are generally first evaluated through imaging. Miller notes that non-invasive CT scans and MRIs often provide the first look at a cyst. In some cases where certain features are concerning or a patient’s personal or family history suggests a higher-than-normal risk of cancer, an endoscopic ultrasound (EUS) may be recommended.

“An EUS involves a thin flexible tube with a camera and ultrasound probe to be passed down a patient’s mouth and guided to the stomach and first part of the intestine,” says Miller, “an EUS allows us to evaluate the entire pancreas and cysts. In addition, we can collect fluid from the cyst and analyze it to accurately determine if it has cancerous potential or not. That same analysis can offer us insight into how the pancreas is performing and identify any genetic markers that may or may not indicate a likelihood of cancer developing.”

Whether it’s gathered through a CT scan, MRI, or an EUS, the information obtained allows the patient’s provider to determine the next best steps for the individual.

“Very often we’ll determine that there’s only a very low risk for the cyst to progress towards cancer,” says Miller. “Often, we will recommend more imaging at a later time just to monitor a cyst and evaluate for risk of progression towards cancer in the future. In the rare cases where the imaging suggests cancer or we think that a cyst—even if it appears non-cancerous—might contribute to ongoing problems, we will send a patient for a surgical consult.”

What Causes Pancreatic Cancer?

While there’s no clear understanding of what causes pancreatic cancer, there are known risks and contributing factors.

These include:

Genetics: roughly 1 in 10 pancreatic cancers are hereditary and are associated with several different types of cancers including pancreatic, breast, ovarian, colorectal, and melanoma.

Long-standing inflammation of the pancreas: diseases of the pancreas and other diseases and conditions such as diabetes and gallstones, that cause ongoing inflammation of the organ have been shown to contribute pancreatic cancer.

Environmental and lifestyle exposures: smoking, heavy alcohol use, obesity, and exposure to chemicals or pesticides have all been linked to pancreatic cancer.

Certain health conditions or factors: individuals with Peutz-Jeghers syndrome, CDKN2A mutation, BRCA 1-2 gene, and carriers of PALB2, ATM, MLH, MSH2 or MSH6 with at least one affected first-degree blood relative (e.g., parent, sibling, child).

Treating Pancreatic Cancer

Pancreatic cancer tends to grow into nearby organs and tissues and can even break away from its initial location and form new tumors in other parts of the body, so treating it requires a team of physicians across multiple specialty areas. Treatment teams often include a medical oncologist, surgical oncologist, radiation oncologist, gastroenterologist or interventional endoscopist, interventional radiologist, diagnostic radiologist, primary care physician, pathologist, and a genetic counselor.

Working together, this team evaluates the type and stage of cancer, current symptoms, possible side effects of treatment, and the patient’s overall health. With this understanding in hand, the care team discusses the potential options with the patient and their family. Together, the patient and providers choose the treatment that best suits the needs and goals of the individual.

A recommended treatment plan may include one or more of the following:

  • Surgery
  • Radiation therapy
  • Chemotherapy
  • Endoscopic techniques (implanting a stent, targeted medicine injection, etc.)

Throughout the treatment process, each patient’s condition is regularly monitored with consideration for how the cancer is responding and how well the treatment is being tolerated. Based on input from the patient and the multi-disciplinary care team, treatment may be adjusted and tailored to better meet specific goals and needs.

While you may not have any symptoms from a pancreatic cyst, always bring any concerning symptoms or questions to your doctor.

All About Pancreatic Cysts

Learn about pancreatic cysts and the risk of pancreatic cancer in our webinar recording.

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