Pancreatic cancer is a relatively rare disease, accounting for only 3.7 percent of all new cancer diagnoses. It is, however, one of the most lethal cancers, with fewer than 8.5 percent of patients surviving five years. Furthermore, unlike the rates of many other cancer-related deaths, which have been falling since the 1990s, the rate of deaths due to pancreatic cancer has been increasing since the early 2000s, though the percentage of patients with pancreatic cancer surviving five years has slightly increased over the past 15 years.
Pancreatic cancer is the third leading cause of cancer death in the United States and is projected to be the second leading one within 10 years. (The most common type of pancreatic cancer is adenocarcinoma. Neuroendocrine cancer, which has a better prognosis, represents less than 2 percent of pancreatic cancers.)
The median age at diagnosis of pancreatic cancer is 70, with most cases occurring between the ages of 65 and 74. The disease is slightly more common in men and African American people.
No early detection test
It is not clear why pancreatic cancer is on the rise, but it may have to do with the population’s increasing age and the steady rise in obesity and type 2 diabetes, all of which are associated with pancreatic cancer. Also, while the decrease in breast cancer, colorectal cancer, and cervical cancer may be attributed to the adoption of screening for those cancers, there is no effective early detection test for pancreatic cancer, and universal screening is unlikely to be recommended at this time for a cancer with such a relatively low incidence.
One of the reasons pancreatic cancer has such a low survival rate is that up to 85 percent of patients are diagnosed with a cancer too advanced to be removed surgically. Hence, much of the effort to reduce deaths has been focused on diagnosing the disease earlier by identifying genes associated with pancreatic cancer, or by identifying proteins in the blood indicative of early-stage cancer. At this point, however, widespread genetic testing is not recommended, and blood biomarkers are still under investigation.
How pancreatic cancer is diagnosed
In the earlier stages of pancreatic cancer, most people don’t have symptoms. Eventual signs and symptoms include jaundice, dark urine, pale or gray stools, belly or back pain, unintentional weight loss, and nausea and vomiting—any of which are reason to see a doctor immediately.
If you have symptoms of pancreatic cancer, your doctor will likely ask about your family history and conduct a physical exam focused mainly on the abdomen, since pancreatic cancer can cause swelling of the liver and gallbladder. But because the pancreas lies deep in the abdomen, doctors rely on blood tests and imaging exams such as computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound to determine the presence and extent of a mass. In some cases, additional imaging tests and a biopsy may be warranted.
Blood tests and imaging can show how far the cancer has progressed or how an individual is responding to therapy. The blood tests are used to evaluate the presence of tumor markers, substances that are found in the blood of people who have cancer. The tumor marker most useful in evaluating pancreatic cancer is carbohydrate antigen 19-9 (CA 19-9).
Treating pancreatic cancer
If the cancer is limited to the pancreas, surgery can offer a possible cure. This almost always occurs when the cancer is in the head of the pancreas. The standard surgery is a Whipple procedure, an arduous operation. Studies have found far fewer complications and deaths associated with Whipple procedures performed at hospitals that do a high volume of these surgeries.
Some surgeons perform Whipple procedures laparoscopically, through several small incisions rather than one long incision, which may help patients recover more quickly. Even with surgery, the cancer recurs in up to 70 percent of patients. Adding systemic therapy—radiation, chemotherapy, or a combination of the two—does improve survival.
In patients whose pancreatic cancer has advanced too far for surgery, chemotherapy is the standard of care. Gemcitabine (Gemzar) has been the chemotherapy agent of choice for the past 20 years, and other agents have been used in combination with it. All chemotherapy drugs have the potential for serious side effects.
New treatments on the horizon
Several new treatment approaches are currently being studied. These fall under the umbrella of targeted therapies—drugs that specifically attack cancer cells or the structures that support cancers—and might be useful additions or alternatives to traditional chemotherapy.
There are different types of targeted therapy. Some drugs in this category target epidermal growth factor receptors (proteins that promote cancer cell growth); erlotinib (Tarceva)—currently approved foruse with gemcitabine—works in this way. Other targeted therapies undergoing study include antiangiogenesis agents, which block the growth of blood vessels supporting cancers; drugs, such as PEGPH20, that break down the supportive tissues shielding pancreatic cancers from chemotherapy; and drugs such as demcizumab, that target the stem cells driving cancer growth.
Immunotherapy drugs, which may help patients fight cancers by boosting their immune system, are another area of interest. These include monoclonal antibodies—immune system proteins that target specific molecules—and cancer vaccines, which may boost a patient’s resistance to pancreatic cancer cells. Researchers are also investigating agents that target checkpoints, the molecules that activate an immune response.
At this point, the use of immunotherapy in pancreatic cancer is, for the most part, investigational and limited to clinical trials.
Can pancreatic cancer be prevented?
Though most cases of pancreatic cancer are diagnosed in people with no family history of the disease, it does run in some families. Pancreatic cancer is also associated with certain other diseases and conditions such as diabetes, particularly type 2; chronic pancreatitis; and cirrhosis.
At this point, the only known preventive strategies for pancreatic cancer are maintaining a healthy weight and not smoking. Avoiding certain environmental chemicals, such as those used in dry cleaning and metal-working, is also advisable, as exposure to those chemicals may contribute to pancreatic cancer risk.
The impact of other lifestyle factors on pancreatic cancer risk is not so clear. Diets high in red and processed meats and low in plant-based foods have been implicated in some studies, but other studies have failed to find an association. Likewise, studies are investigating associations between lack of activity and pancreatic cancer risk, as well as between alcohol intake and pancreatic cancer risk. The results so far have been mixed, although chronic alcohol use can lead to chronic pancreatitis and cirrhosis, as well as other conditions known to increase pancreatic cancer risk.
Also see Acute Pancreatitis: What You Should Know.
Published October 18, 2019