CompletedInterventional

Add-Aspirin: the effects of aspirin on disease recurrence and survival after primary therapy in common non-metastatic solid tumours.

The Add-Aspirin trial is investigating whether a simple, inexpensive medicine—aspirin—can prevent cancer from returning after successful initial treatment. It focuses on common cancers that have not spread to other parts of the body, including early-stage breast cancer. Participants who have had surgery, chemotherapy, or radiotherapy to remove their tumours are randomly chosen by a computer to take daily aspirin (either 100 mg or 300 mg) or a placebo (dummy pill). The study is 'double-blind', meaning neither you nor your doctor will know which tablet you are taking. Researchers want to see if aspirin lowers the chance of cancer returning and improves overall survival. Because aspirin is cheap and widely available, discovering that it helps stop cancer recurrence could change cancer care worldwide and offer an easy way to protect patients after their main treatments finish.

At a glance

Status

Completed

Sponsor

University College London

Enrolment target

11,000

Start

01 Mar 2015

Estimated completion

01 Jan 2025

Cancer

What is this study about?

Aspirin is one of the most common and well-known medicines in the world, usually taken for pain relief or to protect against heart attacks and strokes. Over recent years, doctors have noticed that people taking regular aspirin for their heart often seem to have lower rates of cancer. The Add-Aspirin trial was set up to find out if this simple, low-cost tablet could be used as an extra treatment to keep cancer away for good.

When someone finishes their primary cancer treatment—such as surgery to remove a tumour, followed by chemotherapy or radiotherapy—there is always a small worry that microscopic cancer cells might remain hidden in the body. This study tests whether taking aspirin every day can track down and stop these stray cells from growing into new tumours. It looks at people with non-metastatic cancer, meaning cancer that has not spread to distant parts of the body.

If the study proves that aspirin works, it could transform cancer care across the globe. Unlike many new, highly expensive targeted cancer therapies, aspirin is cheap, easy to make, and available everywhere. A positive result would give doctors an accessible, affordable tool to help many people stay cancer-free after their initial treatments are completed.

Key takeaways

The trial tests whether daily aspirin stops cancer from coming back after primary treatment.
It is open to people treated for early-stage solid tumours, including breast cancer.
Participants take either 100 mg aspirin, 300 mg aspirin, or a dummy pill (placebo) daily.
Neither you nor your doctor will know which group you are in during the trial.
Treatment lasts for about five years with regular health check-ups and monitoring.
Taking part is voluntary, and you can withdraw at any time without affecting your NHS care.

Who may be eligible?

This trial is open to people aged 16 and over who have finished their main treatment for certain common cancers, such as early-stage breast cancer. To take part, you must have had surgery to completely remove the main tumour, with healthy tissue left around the edges. There must be no sign that the cancer has spread to distant parts of your body.

For the breast cancer group, participants need to have completed standard care, which may include surgery on the breast and armpit lymph nodes, followed by radiotherapy or chemotherapy if recommended. People are generally eligible if their cancer had reached nearby lymph nodes or had certain higher-risk features, such as being grade 3, hormone-receptor negative, or HER2-positive.

You also need to be reasonably active and able to look after yourself in daily life (what doctors call a good performance status). You may not be able to take part if you have signs of remaining cancer, if you have a medical condition that makes taking aspirin unsafe, or if your cancer has already spread to other organs.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 16 or older.
I have had surgery to completely remove my primary tumour with clear margins.
My cancer has not spread to distant parts of my body.
I have completed my planned initial chemotherapy or radiotherapy.
I am well enough to carry out normal daily activities and care for myself.

Answer every question to see your result.

What does participation involve?

If you join the Add-Aspirin trial, a computer will randomly place you into one of three groups. You will take either a low dose of aspirin (100 mg), a higher dose (300 mg), or a dummy tablet called a placebo once a day. Neither you nor your research team will know which tablet you are receiving, ensuring the results are fair and reliable.

You will take the tablets daily for around five years. During this time, you will have regular clinic check-ups with the hospital research team to see how you are feeling, monitor any side effects, and check for any signs of your cancer returning. These visits often line up with your normal post-treatment NHS follow-up appointments. You will have routine blood tests and physical exams, and the team will stay in touch with you for several years after you stop taking the tablets to track your long-term health.

Potential risks and benefits

Taking part may or may not help you directly, as researchers do not yet know if aspirin prevents cancer from returning, and you might receive the dummy pill. However, your participation will provide vital answers that could help future cancer patients worldwide. Aspirin can cause side effects, most commonly stomach irritation, indigestion, or an increased risk of bleeding and stomach ulcers. Your study team will monitor you closely and can give you medicines to protect your stomach. Joining the trial is entirely your choice, and you are free to leave at any time without it affecting your standard NHS care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Medical Research Council Clinical Trials Unit (MRC CTU)
City only
London, England

Common questions

What is a placebo?

A placebo is a dummy tablet that looks and tastes identical to the real medicine but contains no active drug. It helps researchers test whether the effects seen are genuinely caused by the aspirin.

Can I just buy aspirin from the chemist instead of joining?

Doctors advise against taking daily aspirin on your own. Aspirin carries risks such as stomach bleeding, and we do not yet know if it truly prevents cancer recurrence. In the trial, your health will be safely monitored.

Will taking part interfere with my other cancer treatments?

You enter the trial after completing your primary surgery and chemotherapy. You can usually continue other long-term maintenance therapies, like hormone therapy, while taking part. Your doctor will check for any clashes.

How long will I need to take the study tablets?

Most participants take their assigned daily tablets for about five years, followed by regular check-ups to monitor their long-term health.

What happens if I get side effects from the tablets?

You should report any symptoms, like tummy pain or unusual bruising, to your trial team immediately. They can offer treatments to help protect your stomach, change your dose, or stop the study pills if necessary.

How to find out more

Olawale Tijani

mrcctu.add-aspirin@ucl.ac.uk +44 (0)207 670 4892 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.