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Genetic testing

Tumour genomic profiling

Sequencing a cancer’s own DNA to find targetable weaknesses - now a routine part of modern oncology.

Key facts

At a glance

  • The distinction: this tests the tumour’s acquired mutations, not your inherited DNA - though it can occasionally flag inherited findings needing follow-up.

  • What it finds: driver mutations matched to targeted drugs, immunotherapy markers, and trial eligibility.

  • The sample: usually existing biopsy tissue; liquid biopsy (blood-based tumour DNA) is an option where tissue is scarce.

  • Results: typically two to four weeks - worth building into treatment planning conversations early.

  • Follow-up: your oncologist matches findings to licensed drugs and clinical trials; some findings prompt referral for germline testing.

The full picture

What this test involves, and how to get it

Tumour genomic profiling sequences the cancer itself, reading the acquired mutations that drive its growth - a fundamentally different question from inherited-risk testing, though the two occasionally meet. The purpose is therapeutic matchmaking: specific alterations pair with specific drugs (EGFR and ALK in lung cancer, BRAF in melanoma, HER2 amplification, BRCA-related repair defects that unlock PARP inhibitors), and broader signatures - tumour mutational burden, mismatch repair deficiency - predict immunotherapy benefit. Profiling ranges from small single-gene tests to large panels of several hundred genes and, through the NHS Genomic Medicine Service, whole genome sequencing for defined cancers. Testing usually runs on existing biopsy tissue; where tissue is exhausted or biopsy is difficult, liquid biopsy - tumour DNA fished from a blood sample - offers a workable alternative for several targets.

Practicalities worth knowing: NHS profiling is standard of care in many cancers, ordered by your oncology team through genomic laboratory hubs, with turnaround typically two to four weeks - reasonable to ask about at diagnosis rather than after first-line treatment is set. Private oncology offers the large commercial panels with similar timelines for patients seeking broader profiling or trial-matching, with costs confirmed upfront. Two honest footnotes: a targetable finding does not always mean an accessible drug - some matches lead to trials rather than prescriptions - and profiling sometimes surfaces variants that look inherited, triggering a recommendation for proper germline testing with counselling. The report is a technical document; its meaning emerges in the oncology consultation that pairs it with your actual treatment options.

A quiet reminder

This guide is for information, not medical advice.

Your own clinician knows your history and can tell you which parts apply to you. Next review of this page: 2027-09-27.

Frequently asked

Common questions about Tumour genomic profiling.

Quick, plain-English answers to what people ask us most.

  • What is Tumour genomic profiling?

    Tumour genomic profiling is a genetic test that looks at specific DNA information relevant to a particular condition, inherited risk, or family planning question. It is usually considered when there is a personal or family history that makes this information clinically relevant. Genetic counselling is often recommended alongside testing to help you understand what a result would mean.

  • Why would someone need this test?

    This type of testing is typically used to assess carrier status, inherited risk, or a specific genetic cause for a condition already suspected on clinical grounds. It may be recommended by a GP, specialist, or fertility clinic depending on the context. The decision to test is usually made together with a healthcare professional, given the personal implications involved.

  • Do I need to prepare for this test?

    Most genetic tests only require a simple blood sample or saliva swab, with no special preparation such as fasting needed. What matters more is having a pre-test conversation, often with a genetic counsellor, about what the possible results could mean for you and your family. This helps you make an informed decision before proceeding.

  • What happens during the test?

    A blood sample or saliva swab is taken and sent to a specialist genetics laboratory for analysis. This part of the process is quick and generally painless. The laboratory work itself, including sequencing and interpretation, is what takes the most time.

  • How long do results take?

    Genetic test results generally take longer than routine blood tests, often several weeks, because of the specialised laboratory analysis and interpretation involved. Your clinician or genetic counsellor will give you a realistic timeframe when the test is arranged. Results are usually discussed with you in a dedicated follow-up appointment rather than by letter alone.

  • What do the results mean, and what happens next?

    Results are usually explained by a geneticist or genetic counsellor, who can put the finding into context and discuss any implications for you and, where relevant, your family members. Next steps vary widely depending on the specific result and may include further testing, specialist referral, or reproductive planning advice. It is normal to need time and support to process this kind of information.

  • Is genetic testing available privately, and how much does it cost?

    Yes, many genetic tests can be arranged privately, often with shorter waits than some NHS genetics pathways depending on the specific test and local services. Cost varies by provider and confirmed before booking. Private genetic counselling is usually included or available alongside testing to support you in understanding the result.

  • Is this type of test accurate?

    Modern genetic testing carried out in accredited laboratories is highly accurate for detecting the specific changes it is designed to look for. However, genetics is complex, and a result is not always straightforward to interpret in isolation - context from a genetic counsellor or specialist is important. Very rarely, further confirmatory testing may be recommended.

  • How do I book this test privately?

    You can usually arrange this through a private genetics clinic or fertility service, either with a referral or via self-referral depending on the provider. Pre-test counselling is typically arranged as part of the process.