RecruitingObservational

Diet-driven gut microbiome and outcome in patients with early-stage triple-negative breast cancer undergoing neoadjuvant chemotherapy and immunotherapy

This study, called CAPTIVATE, is for women with early-stage triple-negative breast cancer. This type of cancer is harder to treat than others. Doctors are looking at how the bacteria in a patient's gut, known as the gut microbiome, might affect how well chemotherapy and a new treatment called immunotherapy work. They also want to see if eating certain foods could change these gut bacteria and potentially improve treatment results. The study aims to understand these links better, hoping to find new ways to help patients in the future. It’s important to note that this is a research study, and direct personal benefits are unlikely.

At a glance

Status

Recruiting

Sponsor

Barts Health NHS Trust

Enrolment target

300

Start

01 Nov 2025

Estimated completion

01 Nov 2032

Stage I-III Triple Negative Breast Cancer

What is this study about?

This research study is focusing on a type of breast cancer called triple-negative breast cancer, often referred to as TNBC. It's a bit different from other breast cancers and can sometimes be more challenging to treat. Doctors currently use chemotherapy for many patients, and a newer treatment called immunotherapy (pembrolizumab) has recently been shown to improve outcomes for some with this cancer. This study wants to understand why some people respond better to these treatments than others.

The main idea behind this study is to explore the 'gut microbiome'. This is the name for all the tiny bacteria and other microbes that live in our digestive system. We're learning that these microbes play a big role in our overall health and can even affect how our immune system works and how our bodies react to medicines. Researchers believe that these gut bacteria might influence how well chemotherapy and immunotherapy work for breast cancer patients. They are also very interested in whether changes to what we eat could, in turn, change these gut bacteria and lead to better treatment results.

So, this study will carefully look at the gut bacteria, diet, and how patients respond to their cancer treatment. The goal is to see if there are links between them. For example, could certain types of gut bacteria or certain diets lead to better treatment outcomes or reduce the chance of the cancer coming back? The hope is that by understanding these connections, we might, in the future, be able to advise patients on specific diets or other ways to change their gut bacteria to improve how their cancer treatment works.

Key takeaways

Researches how gut bacteria link to triple-negative breast cancer treatment.
Aims to see if diet changes could improve treatment outcomes.
Involves providing stool samples and completing questionnaires.
Will not change your current cancer treatment plan.
Unlikely to offer direct personal benefit, but may help future patients.

Who may be eligible?

This study is open to women aged 18 or older who have been diagnosed with early-stage triple-negative breast cancer. Your doctors must have planned for you to receive chemotherapy, either with or without immunotherapy, before surgery – this is called neoadjuvant treatment. You also need to have breast tumour samples available from your diagnosis for the study to analyse.

There are a few reasons why you might not be able to join. These include having received previous treatments for this same breast cancer within the last five years, or if you've recently taken antibiotics (within 14 days before starting the study). You also can't take part if your cancer has spread to other parts of your body (distant metastases).

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.

Are you female and aged 18 or older?
Have you been diagnosed with early-stage triple-negative breast cancer?
Are you due to start chemotherapy (with or without immunotherapy) before surgery?
Have you NOT taken antibiotics in the last 14 days?
Has your cancer NOT spread to other parts of your body?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will have a few extra steps alongside your usual cancer treatment. You'll be asked to provide stool (poo) samples: once before you start your chemotherapy treatment, and again after you finish it. The study will also use some of the tumour samples that are already collected as part of your standard care, for example, from your initial biopsy and any remaining tumour after surgery.

Some patients might also be asked if they are willing to provide additional, small tumour samples during their treatment. You'll complete some questionnaires about what you eat and how your memory and thinking skills (cognitive function) are. These will be done at the start of your treatment, at the end of chemotherapy, and periodically during your follow-up appointments. All of these samples and questionnaire answers will help the researchers understand the link between your gut bacteria, diet, and how you respond to treatment. All your standard treatment and follow-up will happen at your NHS hospital.

Potential risks and benefits

It's unlikely that you will directly benefit from taking part in this study, as the results are for research purposes, not to guide your current medical care. However, the information gathered could help many people with breast cancer in the future. The study involves very little risk. You'll have blood samples taken, which might cause a little discomfort, bruising, or rarely, a slight infection. It's important to remember that joining the study is completely up to you, and saying no will not affect your care in any way. You can also withdraw at any time.

Locations (6)

St Bartholomew's Hospital
Approximate
London, United Kingdom
Belfast City Hospital
Approximate
Belfast, United Kingdom
Greater Glasgow and Clyde
City only
Glasgow, United Kingdom
NHS Lothian
Approximate
Edinburgh, United Kingdom
Oxford University Hospitals
City only
Oxford, United Kingdom
Imperial College Healthcare NHS Trust
Unverified
London, United Kingdom

Common questions

What is triple-negative breast cancer?

It's a type of breast cancer that doesn't have certain features (receptors) that are common in other breast cancers, which means some common treatments won't work for it.

What is a 'gut microbiome'?

It's the community of trillions of tiny bacteria and other organisms that live in your digestive system, playing a role in your health.

Will taking part change my cancer treatment?

No, your treatment plan will stay exactly the same. The study is collecting information about your gut bacteria and diet alongside your standard care.

What kind of samples will I need to provide?

You'll be asked for stool (poo) samples at specific times, and the study will use tumour samples from your routine care.

How long will the study last?

The study is expected to run from October 2025 to November 2032, involving follow-up over several years after your treatment.

How to find out more

Melissa Phillips

bci-captivate@qmul.ac.uk - Official trial record

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