Daily Aspirin Use May Lower Colorectal Cancer Recurrence
Taking a small daily dose of aspirin could significantly lower the chances of colorectal cancer returning after surgery, according to a substantial study looking into the benefits of this common pain reliever.
Researchers in Sweden discovered that patients who consumed a low daily dose of aspirin after tumor removal experienced a 50% reduction in cancer recurrence over a three-year period compared to those taking a placebo.
This trial focused on patients with specific genetic mutations in their tumors that enhance the effectiveness of aspirin’s anti-cancer properties, and about 40% of colorectal cancer patients fall into this category.
Prof. Anna Martling, who spearheaded the study at the Karolinska Institute in Stockholm, commented, “I think this will change clinical practice. If you had these mutations, the risk of cancer returning was cut by more than 50%. It’s really a significant finding.”
Globally, colorectal cancer affects nearly 2 million individuals each year, with over 40,000 diagnoses in the UK. Many undergo surgery to remove tumors, but despite improvements in treatment options like chemotherapy and radiotherapy, there’s always a chance for recurrence if remnants of the cancer are left behind.
Rates of bowel cancer are on the rise among individuals under 50 worldwide. While the exact causes remain unclear, researchers have speculated that factors such as poor diet, obesity, insufficient physical activity, and toxins produced by gut bacteria could be contributing.
Previous studies have indicated that aspirin might help prevent colorectal cancer in people at high risk, particularly those with hereditary conditions such as Lynch syndrome. However, it was previously uncertain whether it could also lower the risk of recurrence post-surgery.
Martling and her team enlisted over 3,500 patients who had their colorectal tumors surgically removed across hospitals in Sweden, Norway, Denmark, and Finland. Genetic testing on 2,980 patients revealed that 1,103, or about 37%, had mutations in genes linked to a biological pathway known as PI3K, which is associated with colorectal cancer.
Participants with these mutations were randomly assigned to take either 160 mg of aspirin daily or a placebo for three years following surgery. Those on aspirin saw a 55% lower likelihood of cancer recurrence compared to the placebo group.
The mechanism of aspirin appears to involve reducing inflammation, disrupting the PI3K pathway, and inhibiting the activity of blood platelets, which can conceal tumor cells from the immune system.
Martling highlighted the relevance of conducting genetic tests on all colorectal cancers, so that patients who could benefit from aspirin receive it accordingly. “It’s a widely accessible and very inexpensive drug,” she added.
Aspirin has been available for over a hundred years, yet using it for extended periods does carry risks. In this trial, four patients encountered serious side effects likely related to aspirin, such as allergic reactions, gastrointestinal bleeding, and in one case, a brain bleed. There were four fatalities during the trial, one of which might be linked to aspirin use. The full details are found in the New England Journal of Medicine.
Dr. Catherine Elliott, the director of research at Cancer Research UK, remarked, “Preventing cancer cases saves lives, and discovering new methods to achieve this is crucial in our fight against cancer. There’s growing evidence that low-dose aspirin can provide protection against bowel cancer for certain individuals.”
She also noted, “The Cancer Research UK-funded CaPP3 trial demonstrated similar benefits for those with Lynch syndrome, an inherited condition that raises cancer risks. We need larger, well-designed studies like CaPP3 and this recent research to understand better who would gain the most from taking aspirin to lead longer, healthier lives, free from cancer worries.”
