MONDAY, Sept. 28, 2015 (HealthDay News) -- Millions of Americans already take a low-dose daily aspirin to help shield their hearts. Now, a new study suggests the same inexpensive pill might extend survival for patients battling cancers of the gastrointestinal tract -- including tumors of the colon and esophagus.
"Given that aspirin is a cheap, off-patent drug with relatively few side effects, this will have a great impact on health care systems as well as patients," study lead author Dr. Martine Frouws, of Leiden University Medical Center in the Netherlands, said in a news release from the European Cancer Congress (ECC).
The study was presented Sunday in Vienna at the annual ECC meeting.
One U.S. expert said the findings aren't surprising.
"For many years, gastroenterologists and oncologists have known that aspirin can improve survival in certain types of hereditary colon cancer," said Dr. Arun Swaminath, director of the inflammatory bowel disease program at Lenox Hill Hospital in New York City.
He also noted that earlier this year, the influential U.S. Preventive Services Task Force "suggested that certain populations at average risk of colon cancer may benefit from taking low-dose aspirin."
In the new study, Frouws' team looked at outcomes for more than 13,700 patients diagnosed with a gastrointestinal cancer between 1998 and 2011. Patients were tracked for an average of more than four years.
The most common types of cancers seen were colon, rectum and esophagus, and about 28 percent of the patients survived for at least five years.
According to the researchers, people who took daily low-dose aspirin after their diagnosis were twice as likely to survive as those who did not. This benefit of taking aspirin was seen after the researchers adjusted for other factors such as sex, age, cancer state, type of treatment, and other health conditions.
Just how might aspirin help keep these cancers at bay? Frouws' team believe the drug may boost the immune system's ability to detect and destroy circulating tumor cells in the blood.
"Medical research is focusing more and more on personalized medicine, but many personalized treatments are expensive and only useful in small populations," Frouws said. "We believe that our research shows quite the opposite -- it demonstrates the considerable benefit of a cheap, well-established and easily obtainable drug in a larger group of patients, while still targeting the treatment to a specific individual."
For his part, Swaminath cautioned that it's still too early to assess the full scope of aspirin's anti-cancer effect.
For example, "it's not clear in this study if using aspirin prevents these cancers, only that those taking aspirin is tied to better survival," he said.
And he noted that, like every drug, low-dose aspirin comes with risk.
"The risk of taking aspirin includes gastrointestinal bleeding and ulcers, so the decision to take it should be done with the aid of a physician," Swaminath said.
Dr. Tony Philip is a cancer specialist at North Shore-LIJ Cancer Institute in Lake Success, N.Y. He noted that 70 percent of the gastrointestinal cancer patients included in the new study had colon tumors, and aspirin's effect in those cancer has already been known. Only further analysis will determine for sure if aspirin has a benefit for patients suffering from other gastrointestinal cancers, Philip said.
However, "given aspirin's affordability, availability, low toxicity profile and cardio-protective properties -- patients and providers will be excited to see further studies like this," he said.
Experts also note that findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
The U.S. National Cancer Institute has more about aspirin and cancer risk.