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For years, scientists have said that aspirin has the potential to protect people from the deadly grip of colorectal cancer. But only now are they unlocking just how this common pain reliever may pull off such a feat.

Researchers have discovered that aspirin's cancer-fighting prowess hinges on rallying the body's immunity to combat malignant cells.

Aspirin Heightens Immune Surveillance of Tumors

Colorectal cancer is a type of cancer that affects either the large intestine or the rectum. Globally, it is the third most common type of cancer and the second leading cause of cancer-related death. Colorectal cancer accounts for roughly one in 10 of all cancer cases, according to the World Health Organization (WHO). In 2020, there were nearly 2 million new cases of colorectal cancer — frequently detected late, limiting treatment possibilities — worldwide, and it caused more than 930,000 deaths, according to WHO.

A recent study published in Cancer, a peer-reviewed journal of the American Cancer Society, suggested that aspirin might prevent colorectal cancer by boosting certain aspects of the natural immune response against malignant cells. Researchers analyzed 238 colorectal cancer patients who underwent surgery between 2015 and 2020, with 12 percent being regular aspirin users. Tissue samples revealed aspirin users had less cancer spread and higher tumor immune cell infiltration than non-users.

Further lab analysis showed aspirin exposure increased the expression of the CD80 protein on certain immune cells. CD80 is known for regulating cell activity, and its increased expression enhanced the immune cells' ability to detect tumor-associated proteins.

Rectal cancer patients using aspirin exhibited higher CD80 levels in healthy rectal tissue, suggesting aspirin stimulated increased immune surveillance.

"Our study shows a complementary mechanism of cancer prevention or therapy with aspirin besides its classical drug mechanism involving inhibition of inflammation," Dr. Marco Scarpa, a general surgeon at the University of Padova Hospital in Italy and the study's principal investigator, said in a press release.

Aspirin may also protect against colorectal cancer by reducing inflammation, which can impair the immune system's ability to fight cancer, Nazlie Latefi, who holds a doctorate in neuroscience, biochemistry, and molecular biology and is not associated with the study, told The Epoch Times.

Further research is needed to understand the full implications of new treatments or prevention strategies.

From Pain Relief to Disease Prevention

Aspirin's history dates back around 3,500 years to ancient Egyptians using willow bark, a natural source of the compound. However, it wasn't synthesized as a drug until 1897 by Bayer chemist Felix Hoffmann, eventually becoming one of the world's most widely used medications.

Evidence shows this naturally occurring substance is proving effective against significant health threats.

One study linked low-dose aspirin use (81 milligrams at least three times weekly) to significantly reduced risk of a certain type of hormone-fueled breast cancer in over 57,000 women followed for eight years. "This is the first report to suggest that the reduction in risk occurs for low-dose aspirin and not for regular-dose aspirin and only among women with the hormone receptor-positive/HER2-negative subtype," the authors wrote.In low 75- to 100-milligram doses, aspirin can reduce heart attack risk by decreasing blood clot formation in diseased arteries. Thus, those who've had a heart attack or stroke are often advised to take daily aspirin to prevent blood clots.

Despite the benefits, all medications, including aspirin, carry potential risks. Though typically safe, aspirin can cause gastrointestinal ulcers, increased bleeding risk from blood thinning, and allergic reactions like hives and asthma in some people.