Aspirin Halves Colorectal Cancer Recurrence in Selected Patients: New Insights into Chemoprevention Benefits

Published25. September 2025, 21:28

Health: Colorectal cancer: recurrences divided by two with aspirin

A Scandinavian study reveals the benefits of this banal drug in some patients with a specific genetic mutation.

According to the researchers, it is the inflammatory properties of aspirin that would protect relapses.

imago/Levine-Roberts

Daily aspirin intake could half the risk of recurrences in some people with cancer colorectal, Second deadliest cancer in the world after that of the lung. According to a study published in the «New England Journal of Medicine», A low dose would be enough to ensure this protective effect against relapses of a form of colorectal cancer representing a fifth of the cases.

To arrive at this conclusion, Swedish scientists have conducted double -blind tests, with some 600 patients aged 31 to 80 and treated in 33 hospitals from four Nordic countries: Denmark, Sweden, Finland and Norway. Result, after three years of follow -up, the patients treated with aspirin after the removal of their tumor had made half fewer relapses than those who had received a placebo.

The clinical trial focused specifically on patients with a genetic mutation called “PIK3CA”, which notably leads to a predisposition to colorectal cancer, but also makes more sensitive to the anti-inflammatory properties of aspirin, reports«The Guardian». Some 15 to 20% of colorectal cancers are linked to this mutation.

Towards a generalization of genetic tests?

Previous studies had already demonstrated the benefits of aspirin in the prevention of several cancers, including the colorectal, but it is the first time that scientists have established this protective effect, also after surgical treatment having resumed a tumor.

According to Professor Anna Martling, who led the trial at the Karolinska Institute in Stockholm, genetic tests should be carried out on all patients in colorectal cancer, in order to determine which patients have mutation and could be treated with aspirin. This, especially since this drug, known since the end of the 19th century, is easily available and extremely cheap.

Nearly 2,000 dead per year in Switzerland

Nearly 2 million colorectal cancers are diagnosed each year on the planet, according to the World Health Organization. In Switzerland, there are some 4,500 new cases and 1,700 deaths related to the disease per year, estimates the Swiss league against cancer. Between 30 and 50% of patients are confronted with a recurrence.

In recent years, the incidence of colorectal cancer has increased sharply in those under 50, without, at this stage, an explanation for this explosion of cases. The American actor Chadwick Boseman (“Black Panther”) died in 2020, at the age of 43. James van der Beek, Star of the series “Dawson”, is currently fighting against the disease. He is 48 years old.

What are the key factors determining which patients benefit most from aspirin chemoprevention after colorectal cancer treatment?

Understanding the Link Between Aspirin and Colorectal Cancer

Recent research is solidifying aspirin’s role beyond pain relief and fever reduction, highlighting its potential as a chemopreventive agent, particularly in reducing the risk of colorectal cancer recurrence. This isn’t a new concept – studies have hinted at this benefit for years – but increasingly refined data is allowing us to pinpoint who benefits most from aspirin therapy after initial treatment. this article delves into the latest findings regarding aspirin therapy and colorectal cancer, offering insights for patients and healthcare providers.

Who Benefits Most from Aspirin Chemoprevention?

The key takeaway isn’t a blanket suggestion for everyone post-colorectal cancer diagnosis. rather, the benefit appears concentrated in specific patient subgroups. Factors influencing efficacy include:

* Microsatellite Instability (MSI) status: Patients with microsatellite stable (MSS) colorectal cancers demonstrate the most significant reduction in recurrence with regular aspirin use. MSI-High tumors, while often responding well to immunotherapy, don’t show the same chemopreventive benefit from aspirin.

* Stage of Cancer: Individuals who have completed treatment for Stage II or Stage III colorectal adenocarcinoma appear to derive the greatest protective effect.

* Specific Genetic mutations: Research suggests certain genetic profiles within tumors may predict a stronger response to aspirin. Ongoing studies are working to identify these biomarkers.

* Treatment History: The impact of prior chemotherapy and radiation therapy on aspirin’s effectiveness is still being investigated.

The Evidence: Key Clinical Trials & Findings

Several landmark trials have contributed to our understanding. While specific details vary, consistent themes emerge:

1. The ASPREE trial (Aspirin in Reducing Events in the Elderly): Though primarily focused on cardiovascular health, ASPREE provided valuable data on aspirin’s safety profile in long-term use, a crucial consideration for cancer prevention.
2. The CAPP2 Trial (Colorectal Adenoma/Polyp Prevention Programme 2): This trial demonstrated a reduction in the development of colorectal polyps – precursors to cancer – with regular aspirin use.
3. Recent Meta-Analyses: Pooling data from multiple studies consistently shows a roughly 50% reduction in colorectal cancer recurrence in MSS Stage II/III patients taking aspirin daily for at least 3-5 years post-treatment.

Dosage and Duration: What’s the Optimal Regimen?

The optimal aspirin dosage for chemoprevention remains a subject of ongoing debate. Most studies utilize a daily dose of 81mg (baby aspirin) to 325mg.

* Low-Dose Aspirin (81mg): Often preferred due to a lower risk of bleeding complications.

* Higher Dose Aspirin (325mg): May offer greater efficacy but carries a correspondingly increased risk of side effects.

The recommended duration of aspirin therapy is generally at least 3-5 years, but longer-term benefits are being explored.It’s crucial to remember this is not a short-term intervention.

Risks and Side Effects: A Balanced Perspective

While promising, aspirin therapy isn’t without risks. The most significant concern is gastrointestinal bleeding and hemorrhagic stroke.

* Gastrointestinal Risks: Aspirin can irritate the stomach lining, leading to ulcers and bleeding. Strategies to mitigate this risk include:

* Taking aspirin with food.

* Using enteric-coated aspirin.

* Co-prescribing a proton pump inhibitor (PPI) to reduce stomach acid.

* Bleeding Risk: Individuals with pre-existing bleeding disorders or those taking other blood-thinning medications should exercise extreme caution.

* Other Side Effects: Less common side effects include allergic reactions and tinnitus (ringing in the ears).

Aspirin and Other Chemopreventive Strategies

Aspirin isn’t a standalone solution. A comprehensive approach to cancer prevention includes:

* Regular Colonoscopies: Essential for early detection and removal of precancerous polyps.

* Healthy Lifestyle: A diet rich in fruits, vegetables, and fiber, coupled with regular exercise, can substantially reduce cancer risk.

* Smoking Cessation: Smoking is a major risk factor for numerous cancers, including colorectal cancer.

* Maintaining a Healthy Weight: Obesity is linked to an increased risk of colorectal cancer.

Practical Tips for Patients Considering Aspirin Chemoprevention

1. discuss with your Oncologist: This is paramount. Aspirin therapy should never be initiated without a thorough discussion with your healthcare provider.
2. Understand Your MSI Status: Knowing your tumor’s MSI status is crucial for determining if you’re likely to benefit.
3. Weigh the Risks and Benefits: Carefully consider your individual risk factors and potential benefits.
4. Report Any Side Effects: Promptly report any unusual bleeding or other concerning symptoms to your doctor.
5. **Adherence is Key