Molecular and genetic tumour testing

What is molecular and genetic tumour testing?

Molecular and genetic tumour testing means looking closely at a sample of your cancer in the laboratory to find specific changes in its genes, or certain proteins it makes. It does not test the genes you were born with — it tests the cancer itself. (Tests for inherited risk genes you may pass on in a family are a different thing.)

Cancers grow because of faults in their genes. Knowing which faults are driving a particular cancer can sometimes help your team choose a treatment aimed at that fault — this is called targeted or personalised treatment. The test can be done on tissue already taken at a biopsy or operation, and sometimes on a blood sample that picks up tiny fragments of cancer DNA (a liquid biopsy).

It is important to know what this testing can and cannot do. It can tell your team useful things about your cancer and open up treatment options for some people. It cannot find a targetable change in every cancer — many cancers do not have one — and finding a change does not guarantee that a treatment will work for you.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Tissue sample vs liquid biopsy

Your team chooses the right test for your situation; the two are sometimes used together.

Preparing for your test

• The test is usually done on a sample you have already given, so you often do not need to do anything extra.
• If a fresh sample is needed (for example for whole genome sequencing), your team will explain any biopsy and how it will be handled.
• Ask whether testing is being arranged, what it is looking for, and when results are expected.
• Tell your team about previous biopsies or operations, as stored tissue may be usable.
• Ask whether your treatment will start before the results are back, and whether results might change the plan.
• Ask who will explain the results to you and how you will hear about them.

What happens

There is usually no separate appointment for the test itself. A pathologist or laboratory scientist works with a sample of your cancer — most often tissue already taken, sometimes a blood sample — and runs tests in a specialist molecular laboratory.

The laboratory looks for the specific gene changes or proteins your team has asked about. In the NHS this is done through the Genomic Medicine Service, which uses a national list of approved tests. The findings are written into a report that goes to your cancer team, and are often discussed at a multidisciplinary team (MDT) meeting before any decision is made.

Your team then explains what the result means for you: whether it points to a particular treatment, whether it rules one out, or whether no targetable change was found.

Is this test right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

The biggest thing to understand is that a result showing no targetable change is common and expected for many cancers — it is information, not a setback. Ask your team what each possible result would mean, whether enough good tissue is available, how long testing will take, and whether your treatment needs to begin before results return.

Published figures to discuss

Whether a targetable change is found, and whether a matched treatment helps, varies a great deal by cancer type and by the individual. Many cancers have no targetable change. Reliable, comparable figures across all cancers do not exist, so we describe this in words rather than inventing percentages, and your team can give figures specific to your cancer type.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

There is no physical recovery from the test itself. 'Afterwards' is mostly about waiting for the report and understanding what it means with your team. If a fresh biopsy was needed, recovery relates to that procedure, not the laboratory test.

• Feeling anxious while you wait for results
• Being told no targetable change was found, which is common
• Being asked for a repeat sample if there was not enough good tissue
• Hearing the result only after your treatment has already started

Aftercare

• Ask for the result to be explained in plain words, including what it does and does not change.
• Ask whether any targeted treatment found is available to you, on the NHS or through a trial.
• Ask what happens if no targetable change was found, as standard treatments still apply.
• Keep a note of which test was done and what it showed, for any future opinions.
• Ask whether the result has any meaning for your family, and whether a genetics referral is needed.
• Check who to contact if you have questions after your results conversation.

• Name of the test done and what it looked for
• Date results are expected
• Who will explain the results and how
• Whether treatment will start before results return
• Whether a repeat sample might be needed
• A contact for questions about the report

⚠ Get urgent help if…

• New or worsening symptoms while you wait for results — contact your team rather than waiting for the report
• Feeling you cannot cope with the wait or with distressing news — ask your team or clinical nurse specialist for support
• Being offered a treatment based on a result you do not understand — ask for it to be explained before you agree
• Hearing nothing about expected results after the time your team gave you — chase it up
• Being told to pay for a private test that your NHS team has not advised — ask your team first

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

A 'positive' result means a specific change or protein was found that your team can act on — for example by considering a targeted treatment or a trial. It does not promise that the treatment will work, and your team will explain the likely benefit and the alternatives.

A result showing no targetable change is common for many cancers. It does not mean the test failed or that nothing can be done — standard treatments still apply, and your team will plan using the full picture. Sometimes the sample cannot be fully tested, and a repeat sample may be suggested.

A tumour's genetic make-up can change over time, particularly if a cancer comes back or spreads, so a result reflects the sample tested at that point. Your team may repeat testing later, or test a new sample, if the situation changes and a fresh result would alter the plan.

Related tests, treatments or support

Molecular testing is read alongside the original biopsy report, scans and your overall health, usually at an MDT meeting. It is one part of the picture rather than a standalone answer, and is sometimes done together with tests for inherited risk when there is a reason to consider that.

Follow-up & long-term care

Results go to your cancer team and are usually discussed at an MDT meeting before being shared with you. Your team explains what was found and what it means for your treatment, and arranges any next steps such as a targeted treatment, a trial discussion, a repeat sample, or a referral to genetics if relevant.

• Repeat testing may be considered if the cancer returns, spreads or stops responding.
• Keep a record of which tests were done and what they showed for future care or opinions.
• If a trial is being considered, ask how the result fits the trial's entry requirements.

Repeat, follow-on and what comes next

• Repeat or further testing is sometimes needed if the first sample is inadequate or the result is unclear.
• Testing may be repeated later if the cancer changes, returns or stops responding.
• A result may be reviewed by a specialist molecular team before it is acted on.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• A clear, plain-English explanation of what the result means for your treatment.
• Discussion at an MDT before decisions, with a named contact for questions.
• A plan for a repeat sample if the first could not be tested.
• A route to a genetics discussion if an inherited change is suspected.
• Honest information about benefits, side effects and alternatives for any targeted treatment.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• Which test is done — a single gene, a larger panel, or whole genome sequencing.
• Whether a fresh sample or repeat biopsy is needed to provide enough good tissue.
• Whether a tissue or blood (liquid biopsy) sample is used.
• The specialist laboratory's reporting and how quickly a result is needed.
• Any follow-up consultation to explain the result and plan treatment.
• Whether the test is part of an NHS pathway or arranged privately.

• The laboratory fee and exactly which genes or markers are tested.
• Whether a fresh biopsy is needed and that procedure's separate cost.
• The consultant fee to explain the result and plan next steps.
• Expected turnaround time and what happens if the sample cannot be tested.
• What happens, and who pays, if a repeat sample or repeat test is needed.
• Whether the same test is available on the NHS through the Genomic Medicine Service.

On the NHS? Genomic testing of tumours is offered routinely on the NHS through the Genomic Medicine Service when clinically indicated; private testing is sometimes used for speed or choice but should be discussed with your NHS team first.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• What is this test looking for in my cancer, and why now?
• What will the result change about my treatment?
• What happens if it is positive, negative, or unclear?
• Is there enough good tissue, or might I need another sample?
• Will my treatment start before the results come back?
• Could the result point to a clinical trial that might suit me?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my test, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this test not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for molecular and genetic tumour testing

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How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NHS England — Genomic Medicine Service NHS — Genomic testing Cancer Research UK — Testing cancer cells for gene changes (lung cancer example) Cancer Research UK — Biopsy Royal College of Pathologists — Histopathology Macmillan Cancer Support — Biopsy

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.