Sorting out the truth about aspirin

Aspirin may cut pancreatic cancer risk, but should everyone take it?
A new study suggests aspirin cuts the risk of cancer of the pancreas, but recently the FDA advised against healthy people taking a daily aspirin to prevent heart attack and strokes. Fred Hutch researchers help sort out the recommendations. Robert Hood / Fred Hutch

A new study implies that aspirin, an over-the-counter remedy long considered useful in reducing the risk of heart attack or stroke, may also be effective against pancreatic cancer. This news could be a game-changer for a type of cancer, which, while relatively rare, has long been considered fatal because it tends to be diagnosed at a late stage.

Researchers have been investigating the possible protective effect of aspirin on pancreatic cancer for more than a decade. The paper published in the June 24 issue of Cancer Epidemiology, Biomarkers & Prevention shows that, with prolonged use, aspirin may have a fairly robust preventive effect on pancreatic cancer, a type of malignancy that is not only difficult to treat but is also almost always deadly. Reduced risk of pancreatic cancer was associated more closely with low-dose aspirin; researchers speculate that people who take low-dose aspirin may do so more consistently.

Existing aspirin recommendations

Many of the few known risk factors for pancreatic cancer are things that cannot be changed, such as age, gender or ethnicity. Currently, treatment for the disease is daunting at best, and anything that can skew the odds is certainly enticing. However, before recommending aspirin across the board to prevent cancer, it is important to consider the facts.

Last month the U.S. Food and Drug Administration announced that aspirin, long thought a safe, low-cost way to reduce risk of heart attack and stroke, should not be routinely used by people who have no prior history of cardiovascular disease. Low-dose aspirin tablets (80 mg per pill) are often recommended for people who have already experienced a heart attack or stroke or who have been diagnosed with heart disease. The FDA does not, however, support taking aspirin to prevent a first heart attack or stroke. The agency says that in the absence of existing cardiovascular disease, the risks of taking daily aspirin -- which include the increased chance of bleeding in the stomach or brain -- outweigh the benefits.

Is it inflammation?

Today, acetaminophen or ibuprofen are generally the top choices for everyday aches and pains. Most people who regularly take aspirin use the low-dose form, sometimes called “baby” aspirin, for cardiovascular disease. Ibuprofen and aspirin are known as nonsteroidal anti-inflammatory drugs (NSAIDs), which interfere with the production of certain enzymes in the body. This inhibitory action may be responsible for aspirin’s anti-cancer effects. Acetaminophen, while not an NSAID, is an analgesic and fever-reducing drug.

“The main benefit of taking aspirin is in reducing inflammation,” said Dr. Thomas Vaughan, an epidemiologist in the Public Health Sciences Division of Fred Hutchinson Cancer Research Center. According to the American Heart Association, inflammation is a common contributor to heart disease and stroke.

Inflammation is also thought to be a factor in many, but not all, cancers. “It can certainly play a role in pancreatic cancer,” Vaughan said. “For example, chronic pancreatitis is one of the few known risk factors, and there is certainly inflammation there.” In addition, he said, some specific oncogenes -- genes that have the potential to cause cancer -- can be activated by inflammation.

A number of previous studies dating from 2000 and later have looked at the connection between pancreatic cancer and NSAID use, specifically aspirin, with varied results. Researchers in the new study speculate that the older studies may have showed less positive results because the recommendation of regular, low-dose aspirin for cardiovascular disease was not introduced until 1989.

Pancreatic cancer is problematic in that there aren’t many warning signs, and the condition commonly has a poor prognosis, even if diagnosed early. Smoking cigarettes, diabetes, obesity, and pancreatitis can all increase one’s risk of pancreatic cancer; however, many people who develop the disease have none of these issues. In addition, signs of pancreatic cancer do not usually occur until the disease is advanced and can include nonspecific symptoms such as upper abdominal pain, jaundice, loss of appetite, weight loss, depression, and blood clots.

Don’t go it alone

Those who think they may be at risk for pancreatic cancer and are interested in active prevention are encouraged to talk to their doctor before starting aspirin therapy. In addition, those who already are taking aspirin for a heart condition should not discontinue it without checking in with their practitioner. Stopping aspirin therapy abruptly can increase one’s risk of dangerous blood clots.

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Joely Johnson Mork is a Seattle-based freelance health and science writer/editor whose work has appeared in numerous consumer health books, as well as in Prevention and TIME. Her personal essays have been heard on NPR. Mork has a master’s degree in community health education and is a certified yoga instructor.

Solid tumors, such as those of the pancreas, are the focus of Solid Tumor Translational Research, a network comprised of Fred Hutchinson Cancer Research Center, UW Medicine and Seattle Cancer Care Alliance. STTR is bridging laboratory sciences and patient care to provide the most precise treatment options for patients with solid tumor cancers.


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