Liquid biopsy: can it detect cancer coming back?

Source of the announcement: Abu Dhabi Media Office, October 22, 2026. (https://www.mediaoffice.abudhabi/en/health/m42-and-inocras-partner-to-advance-earlier-detection-of-cancer-recurrence-in-the-uae/)

Information checked on October 27, 2026.

After treatment, knowing sooner whether a cancer might return is an important hope. Some liquid biopsies can detect traces of a tumor in the blood before a recurrence becomes visible on imaging. However, this lead time guarantees neither consistent detection nor more effective treatment. In breast cancer follow-up, the benefit of surveillance based on these tests has yet to be established. ASCO, 2026 follow-up guidelines (https://ascopubs.org/doi/full/10.1200/JCO-26-01700)

What does a liquid biopsy look for?

The term covers several tests for substances that come from a tumor and are present in a body fluid. For the follow-up discussed here, it means a blood test looking for small fragments of circulating tumor DNA, also called ctDNA. This is not the same as a tissue biopsy, which removes cells or a piece of tissue. National Cancer Institute, overview of the principle (https://www.cancer.gov/news-events/cancer-currents-blog/2017/liquid-biopsy-detects-treats-cancer)

After treatment, a tiny amount of cancer may remain. Looking for its molecular traces is the basis of testing for molecular residual disease, or MRD. In a tumor-informed approach, the laboratory uses the genetic characteristics of a tumor that has already been analyzed to look for matching traces in the blood. However, not all liquid biopsy tests use this method, and their performance is not interchangeable. ESMO, recommendations on ctDNA (https://doi.org/10.1016/j.annonc.2022.05.520)

What could earlier detection offer?

A blood draw is generally less burdensome than taking another tumor sample and can be repeated to monitor changes. The aim of research is to identify people in whom a recurrence may be developing, then determine whether intervening at that point actually improves their outcomes. National Cancer Institute (https://www.cancer.gov/news-events/cancer-currents-blog/2017/liquid-biopsy-detects-treats-cancer)

Studies in breast cancer have observed a blood signal several months before detection by the usual examinations. Work presented in August 2026 by the Institute of Cancer Research also explores tests that do not require prior analysis of a tumor sample. Nevertheless, the researchers emphasize that the effectiveness of an intervention triggered by this signal still needs to be demonstrated. These findings do not automatically validate another commercial test. Institute of Cancer Research, August 20, 2026 (https://www.icr.ac.uk/about-us/icr-news/detail/new--cheaper-blood-test-could-help-detect-breast-cancer-recurrence-earlier)

Why does liquid biopsy not replace imaging?

The two examinations provide different information:

- Liquid biopsy looks for a biological signal in the blood. It does not produce an image that can locate a lesion.

- Imaging examines structures within the body and can show an abnormality, its size, and its location. The choice of imaging depends on the clinical situation.

In its 2026 ctDNA guidelines, ASCO does not consider the complete replacement of usual examinations by this test to be established. A blood test result must be interpreted alongside the other information in the medical record, not as a universal substitute for CT, MRI, or a biopsy. ASCO, guidelines on ctDNA testing (https://ascopubs.org/doi/abs/10.1200/OP-26-00311)

Nor is detection ahead of imaging consistent. In the c-TRAK TN trial, which involved certain high-risk triple-negative breast cancers, several recurrences occurred without prior detection in the blood. Among many participants referred for intervention after a positive result, the assessment already showed metastases. c-TRAK TN results, Annals of Oncology, 2023 (https://www.annalsofoncology.org/article/S0923753422047354/pdf)

What limitations should be understood?

A negative result does not rule out all residual disease. Some tumors release little DNA into the blood. The amount present may be below the detectable threshold, and the timing of the blood draw matters. A test therefore provides no guarantee that a recurrence will not occur in the future. ESMO (https://doi.org/10.1016/j.annonc.2022.05.520)

A positive result does not, by itself, indicate which treatment would be useful. Identifying a risk and proving that an action improves survival or quality of life are two different steps. The ASCO breast cancer follow-up guidelines published in 2026 emphasize the uncertainty surrounding the clinical benefit of this surveillance. They also mention the anxiety that false-positive results may cause. ASCO, follow-up after treatment (https://ascopubs.org/doi/full/10.1200/JCO-26-01700)

What does the M42–Inocras project in Abu Dhabi announce?

M42's press release is dated October 23, 2026. It announces a collaboration with Inocras on MRDVision, combining tumor genome analysis with personalized blood tests.

The project is to begin with a pilot at Cleveland Clinic Abu Dhabi involving people with certain high-risk breast cancers, including triple-negative and HER2-positive cancers. It aims to generate local data on the test's performance and health-economic value. The possibility of subsequently establishing this capability in M42's laboratories in the United Arab Emirates will be examined based on the results.

This is therefore an evaluation, not an announcement of standard follow-up available to everyone treated for cancer. The press release specifies no public enrollment arrangements, price, or reimbursement. It does not yet report any pilot results. M42, press release of October 23, 2026 (https://m42.ae/media-resources/news/m42-and-inocras-announce-strategic-collaboration-to-advance-earlier-detection-of-cancer-recurrence-in-the-uae-using-whole-genome-powered-mrd-technology/)

What questions should you prepare before considering a test?

To understand a proposal, points to clarify include:

- Which specific test is being proposed, and for what purpose?

- Is this research, or a test used for this indication?

- What evidence relates to this type and stage of cancer?

- What would a positive, negative, or uninterpretable result change?

- Who will explain the result and provide further follow-up?

- What are the costs, turnaround times, and coverage conditions?

If you are considering care abroad, our guide Preparing your care journey (https://www.tebbhelp.com/fr/knowledge/articles/preparer-son-parcours-de-soins) helps organize questions about documents, communications, and follow-up after returning home.

Frequently asked questions

Is this screening intended for everyone?

No. Following up a previously treated cancer and screening someone without a known cancer serve different purposes. Results obtained in one context do not automatically apply to the other. ESMO (https://doi.org/10.1016/j.annonc.2022.05.520)

Are all liquid biopsies experimental?

No. Some ctDNA tests are already used to look for genetic abnormalities that may guide treatment in specific situations. This does not validate their use to monitor for recurrence after every cancer. ASCO, 2026 ctDNA guidelines (https://ascopubs.org/doi/abs/10.1200/OP-26-00311)

Does a negative result allow follow-up to stop?

By itself, it is not a reason to cancel scheduled examinations: an amount of tumor DNA that is too small may go undetected by the test. ESMO (https://doi.org/10.1016/j.annonc.2022.05.520)

Prepare the practical aspects with TebbHelp

For a question about organizing a care journey, you can contact TebbHelp (https://www.tebbhelp.com/fr/contact). Doing so confirms neither access to the pilot nor the medical value of a test. Do not send medical records or an identity document in an initial email. This article provides general information, not personalized advice.

Sources and references

1. ASCO, 2026 follow-up guidelines https://ascopubs.org/doi/full/10.1200/JCO-26-01700

2. National Cancer Institute, overview of the principle https://www.cancer.gov/news-events/cancer-currents-blog/2017/liquid-biopsy-detects-treats-cancer

3. ESMO, recommendations on ctDNA https://doi.org/10.1016/j.annonc.2022.05.520

4. Institute of Cancer Research, August 20, 2026 https://www.icr.ac.uk/about-us/icr-news/detail/new--cheaper-blood-test-could-help-detect-breast-cancer-recurrence-earlier

5. ASCO, guidelines on ctDNA testing https://ascopubs.org/doi/abs/10.1200/OP-26-00311

6. c-TRAK TN results, Annals of Oncology, 2023 https://www.annalsofoncology.org/article/S0923753422047354/pdf

7. M42, press release of October 23, 2026 https://m42.ae/media-resources/news/m42-and-inocras-announce-strategic-collaboration-to-advance-earlier-detection-of-cancer-recurrence-in-the-uae-using-whole-genome-powered-mrd-technology/

8. Preparing your care journey https://www.tebbhelp.com/fr/knowledge/articles/preparer-son-parcours-de-soins

9. Contact TebbHelp https://www.tebbhelp.com/fr/contact

10. Abu Dhabi Media Office, October 22, 2026 https://www.mediaoffice.abudhabi/en/health/m42-and-inocras-partner-to-advance-earlier-detection-of-cancer-recurrence-in-the-uae/