Medical Edge Newspaper Column

Research Under Way to Find Methods to Identify Pancreatic Cancer Before It Spreads

October 7, 2011
Dear Mayo Clinic:
Pancreatic cancer seems like such a deadly disease. Is there a way to find this cancer in the early stages, so it can be successfully treated?

Answer:
Pancreatic cancer, an aggressive disease, is currently one of the leading causes of cancer deaths in the United States. Prompt diagnosis and treatment can improve the chances for long-term survival in some cases. But pancreatic cancer is difficult to detect in its early stages. Research is under way to find methods to identify pancreatic cancer before it spreads.

The pancreas lies at the back of the upper abdomen, behind the stomach, and near the spine. It has two main jobs: secreting enzymes that aid digestion, and producing hormones, including insulin, that regulate the body's blood sugar (glucose).

Cancer of the pancreas is rare and typically affects people older than 50. At this time, the only treatment that offers the possibility of long-term survival is surgically removing the cancer. In nearly three-fourths of people with pancreatic cancer, however, surgery isn't an option because the cancer has spread too far by the time it's found.

The disease usually isn't found early because symptoms typically appear only after the cancer has reached an advanced stage. Common symptoms include upper abdominal pain that radiates to the back, yellowing of the skin and whites of the eyes (jaundice), and unexplained weight loss.

A key strategy for improving outcomes in pancreatic cancer is to find ways to diagnose it when the cancer can still be surgically removed. Efforts at early diagnosis have been hampered by the lack of a blood test to detect early pancreatic cancer. Diagnosis is also difficult because noninvasive imaging studies, such as computerized tomography (CT) scans or magnetic resonance imaging (MRI), don't always reveal small changes in the pancreas that indicate cancer. In addition, they are too expensive to be used as routine screening tests. Detecting small cancers before symptoms appear often requires endoscopic ultrasound or endoscopic retrograde cholangiopancreatography (ERCP) — invasive procedures that aren't widely available.

In an effort to improve early diagnosis, researchers are investigating ways to identify and monitor people at high risk for pancreatic cancer. For example, in rare cases, pancreatic cancer can be inherited, and studies are under way involving families with hereditary pancreatic cancer. Currently only people with two or more first-degree relatives (parents, siblings, and children) with pancreatic cancer are enrolled in such studies. If an early detection model can be found that works in these families, researchers might be able to use that information to develop a screening process for others.

Studies have also shown there may be a link between diabetes and pancreatic cancer. Some studies suggest an increased occurrence of pancreatic cancer in patients with long standing diabetes, while others refute this. Recently there has been a significant interest in patients who develop diabetes within a few months to 3 years of the diagnosis of pancreatic cancer. Such diabetes, especially in the absence of a family history of diabetes and the presence of a family history of pancreatic cancer, may be the effect of pancreatic cancer. This idea led researchers considering using diabetes as a marker to detect pancreatic cancer.

It would be difficult, however, to screen all people who develop diabetes, even in the above-mentioned circumstances, by using tests like a CT scan or MRI. This is because only a small percentage of such diabetics will have pancreatic cancer. More studies are needed to find ways to differentiate between cancer-induced and other forms of diabetes. Studies are ongoing to identify additional markers that point to pancreatic cancer as the cause of newly diagnosed diabetes. If researchers can find a way to distinguish between different forms of diabetes, they may be able to screen those at high risk for pancreatic cancer, possibly catching the tumor earlier.

Other factors that may increase the risk of pancreatic cancer include older age, obesity, chronic inflammation of the pancreas (pancreatitis), and smoking.

Although pancreatic cancer can be very difficult to find early, when it's still treatable, extensive research is being conducted worldwide to improve early diagnosis. Researchers are hopeful these studies will result in a breakthrough that will allow progress to be made against this challenging disease.

— Santhi Swaroop Vege, M.D., Director, Pancreas Clinic, Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minn.