Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study on the Effects of Aspirin and Omeprazole in Obese and Non-Obese Patients with Colorectal Cancer

Registered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of colorectal cancer, a type of cancer that affects the colon or rectum. The study will use a medication called acetylsalicylic acid, commonly known as aspirin, which is a platelet aggregation inhibitor. This means it helps prevent blood cells called platelets from clumping together, which can be important in managing certain health conditions. The trial will also involve the use of omeprazole, a proton pump inhibitor that reduces stomach acid, to help manage any potential side effects of aspirin.

The purpose of the study is to evaluate how a short course of aspirin affects certain enzymes in the body, specifically COX-1 and COX-2, in patients diagnosed with colorectal cancer. The study will compare these effects in patients who are obese and those who are not. Participants will take aspirin in different doses over a short period, and the effects will be observed in both healthy and cancerous tissue.

During the study, participants will take aspirin in varying doses for one week, and the effects on their body will be monitored. The study aims to understand how aspirin works in different individuals, particularly focusing on the differences between those who are obese and those who are not. This research could provide valuable insights into the effectiveness of aspirin in treating colorectal cancer and help tailor treatments for different patients.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Introduction to the trial

    Upon joining the trial, the patient will receive an overview of the study's purpose, which is to evaluate the effect of aspirin on certain enzymes in patients with colorectal cancer.

    The study will compare the effects in patients with different body weights.

  2. Step 2

    Initial assessment

    The patient will undergo an initial assessment to confirm eligibility, including age between 18 and 80 years, a recent diagnosis of colon or rectal cancer, and normal coagulation and biochemical parameters.

    Patients will be categorized into obese or non-obese groups based on their body mass index (BMI).

  3. Step 3

    First medication course

    The patient will begin a one-week course of enteric-coated acetylsalicylic acid (aspirin) at a low dose of 100 mg per day.

    This medication is taken orally and aims to assess its impact on specific enzymes in the blood.

  4. Step 4

    Evaluation after first course

    After completing the first week of medication, the patient will undergo evaluations to measure the effects of the aspirin on the enzymes COX-1 and COX-2 in the blood.

  5. Step 5

    Second medication course

    The patient will start a second one-week course of aspirin, with varying doses depending on the group: 300 mg per day, 100 mg every 12 hours, or continuing with 100 mg per day.

    This course also involves oral administration of the medication.

  6. Step 6

    Final evaluation

    Following the second week of medication, the patient will undergo final evaluations to assess the effects of the different aspirin doses on the enzymes in the blood, healthy colon tissue, and tumor tissue.

Who can join the trial?

4 criteria

  • Must be between 18 and 79 years old.
  • Must have a recent diagnosis of colorectal cancer, which means cancer in the colon or rectum. This diagnosis should be confirmed by a procedure called endoscopy and a detailed tissue study.
  • Must have normal blood clotting and usual blood test results without any significant issues that could affect the study, as determined by the study doctor.
  • If you are in the obese group, your Body Mass Index (BMI) should be 30 or higher. If you are in the non-obese group, your BMI should be 25 or lower. BMI is a measure that uses your height and weight to determine if you are in a healthy weight range.

Who cannot join the trial?

5 criteria

  • Patients who are not diagnosed with colorectal cancer cannot participate. Colorectal cancer is a type of cancer that affects the colon or rectum, which are parts of the large intestine.
  • Patients who are under the age of 18 or over the age of 65 cannot participate.
  • Patients who are part of a vulnerable population, such as those who cannot make decisions for themselves, cannot participate.
  • Patients who are not able to take acetylsalicylic acid (also known as aspirin) cannot participate. Aspirin is a medication used to reduce pain, fever, or inflammation.
  • Patients who have any medical condition that the study doctors believe would make it unsafe for them to participate cannot join the study.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Aspirin: This medication is being used in the trial to study its effects on certain enzymes in the body, specifically COX-1 and COX-2. Aspirin is commonly used to relieve pain, reduce inflammation, and lower fever. In this trial, it is being given to patients with colorectal cancer to see how it affects these enzymes in both healthy and cancerous tissues, as well as in platelets. The study is also looking at whether the effects of aspirin differ between obese and non-obese patients.

What is already known about the treatment

Aspirin – Aspirin is administered orally in the form of enteric-coated tablets. It is widely recognized in medical literature as a common medication used for pain relief, reducing inflammation, and preventing blood clots. In this clinical trial, it is being investigated for its potential role in the chemoprevention and therapy of colorectal cancer, particularly in relation to obesity. Aspirin works by inhibiting the enzymes COX-1 and COX-2, which are involved in the production of substances that promote inflammation and blood clotting. It is classified as a non-steroidal anti-inflammatory drug (NSAID).

Investigated diseases

Colorectal cancer – This disease involves the growth of abnormal cells in the colon or rectum, which are parts of the large intestine. It often begins as small, noncancerous clumps of cells called polyps that form on the inside of the colon. Over time, some of these polyps can become cancerous. As the cancer progresses, it can invade and destroy normal tissue nearby and may spread to other parts of the body. Symptoms can include changes in bowel habits, blood in the stool, and abdominal discomfort. The progression of the disease can vary, with some cases remaining localized while others may spread to distant organs.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-515251-37-00Protocol codePI20/01514Estimated enrolment60 patientsSponsorFundacion Instituto De Investigacion Sanitaria Aragon

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.