An older male taking a pill.Share on Pinterest
New research suggests that low dose aspirin may help enhance your immune system and lower your risk of colorectal cancer. andreswd/Getty Images
  • Aspirin has been shown to protect against colorectal cancer.
  • A new study says it may do this by enhancing the body’s ability to detect cancer cells.
  • Aspirin is not right for everyone and may be most beneficial for those with CVD risk.
  • Your lifestyle choices can also influence your risk for colorectal cancer.
  • Early detection through regular screenings can make colorectal cancer easier to treat.

Studies have shown that taking aspirin may reduce the risk of colorectal cancer. Additionally, other studies suggest that aspirin use may also improve colorectal cancer outlook.

One thing that remains unclear, however, is just how aspirin protects against colorectal cancer.

The main protective mechanisms are thought to be the inhibition of the enzymes that maintain proinflammatory signals, such as prostaglandin‐endoperoxide synthase 1 (COX-1) and prostaglandin‐endoperoxide synthase 2 (COX-2).

But, there are several other interrelated mechanisms that have not yet been elucidated.

According to new research published on April 22, 2024, in the journal Cancer, one of these mechanisms may be that it enhances certain aspects of the immune system.

To learn more about how aspirin might protect against colorectal cancer, Italian researchers looked at tissue samples from 238 people who had surgery for colorectal cancer.

They identified that 12% of these patients were aspirin users.

They then compared tissue samples from cancer patients who had used aspirin with those who hadn’t.

In those who used aspirin, there was less cancer spread to the lymph nodes and higher infiltration of immune cells into tumors.

Further, when the researchers exposed colorectal cancer cells to aspirin in their lab, they saw greater expression of a protein called CD80 on certain immune cells.

This amplified their ability to signal to other immune cells that proteins associated with cancerous cells were present, according to the study authors.

They also found higher CD80 expression in the healthy rectal issue of those patients with rectal cancer. This finding suggests that aspirin creates an environment where the immune system is on the lookout for cancer cells.

The principal investigator on the study — Dr. Marco Scarpa MD, PhD, of the University of Padova — further noted in a press release that absorption of aspirin in the rectum tends to be less than in the rest of the colon.

“Thus, if we want to take advantage of its effects against colorectal cancer, we should think of how to guarantee that aspirin reaches the colorectal tract in adequate doses to be effective,” he said.

The researchers wrote that one of the primary limitations of the study was the fact that it was retrospective and observational, meaning that they were looking back in time to see what had already happened.

According to the authors, this made it impossible to analyze how long people had been taking aspirin prior to their cancer diagnoses.

Additionally, the researchers noted that aspirin use was self-reported and, in some instances, people may have taken aspirin in the past, but it was obscured by the fact that they had stopped using it before entering the hospital for cancer treatment.

Kubanych Takyrbashev, MD, Health & Wellness Advisor at NAO, who was not involved in the study, commented that since it was not a controlled clinical trial — a study in which one group receives the treatment that’s being studied and another comparison group receives a sham treatment — this can also introduce confounding variables and biases.

Confounding variables are uncontrolled variables that could also be causing the observed effect. Biases could tip the balance in favor of a false result.

“Furthermore,” said Takyrbashev, “the mechanisms underlying aspirin’s potential effects on the immune system’s response to cancer cells would require further elucidation through in-depth molecular and cellular studies.”

“Before considering aspirin as a preventive measure against cancer or any other condition, individuals should be aware of the potential risks and side effects associated with its use,” said Takyrbashev.

Long-term aspirin use can increase your risk of gastrointestinal bleeding, ulcers, and other complications, he said.

This is especially true in people who have a history of gastrointestinal issues or bleeding disorders.

“Additionally, aspirin can interact with other medications and might not be suitable for everyone,” said Takyrbashev, “so individuals must consult with a healthcare professional before initiating aspirin therapy.”

Chris McDermott, a Certified Advanced Practice Registered Nurse with Intercoastal Consulting & Life Care Planning, who was not involved in the study, said, “Beyond aspirin, lifestyle choices play a vital role.”

First of all, it’s important to get regular screenings in order to detect precancerous polyps early, he said.

The U.S. Department of Health and Human Services recommends that you get regular screening for colorectal cancer between the ages of 45 and 75.

However, if there is a history of colorectal cancer in your family, they suggest that you get screened even sooner.

According to the agency, early detection can make the disease easier to treat.

In lieu of a colonoscopy, in which a doctor uses a scope to look directly inside your colon and rectum, you may be able to simply provide a stool sample for analysis if you are at average risk of developing colorectal cancer.

McDermott added that eating a diet rich in fiber, fruits, vegetables, and whole grains is also important.

Getting regular exercise, moderating your alcohol consumption, and avoiding smoking can also reduce your risk.

Finally, you should check whether anyone in your family has had the disease. “Genetic factors matter, so be aware of your family’s cancer history,” McDermott concluded.

Studies have shown that taking low dose aspirin on a regular basis can help protect against colorectal cancer.

A new study has found that one way it might provide this benefit is by enhancing the immune system’s ability to detect cancerous cells.

Experts say aspirin is not for everyone since the risks may outweigh the benefits. Patients at risk for CVD are good candidates. However, if you have a history of gastrointestinal issues or bleeding disorders, it may not be right for you.

Other ways to reduce your risk include eating a healthy diet, exercising, drinking only in moderation, and avoiding smoking.

It’s also important to know your family’s medical history and get screened for colorectal cancer following the recommended schedule.