Medical technology
Precision and genomic medicine: tailoring treatment to the individual
Medicine has traditionally treated the "average" patient, with the same drug and dose for everyone with a condition. Precision (or personalised) medicine aims to tailor prevention and treatment to the individual — often using information from their genes. As genetic sequencing has become faster and cheaper, this approach has moved from research into routine care in specific areas. This guide explains what it is and where it genuinely helps.
Education and reference only. This article explains how treatments work in plain language — it contains no doses and is not a substitute for advice from your doctor or pharmacist. Always discuss your own treatment with a qualified clinician.
The idea: from average to individual
Precision medicine uses detailed information about a person — increasingly their genetic makeup, but also other biological and lifestyle data — to guide decisions about prevention, diagnosis and treatment. The insight driving it is that people differ in ways that affect which treatments will work and which will cause harm. Rather than "one size fits all", the aim is to match the right treatment to the right person at the right time. Falling costs of DNA sequencing turned this from an aspiration into a practical tool.
Genomics in cancer
The clearest current success is in cancer. Tumours are driven by specific genetic changes, and testing a tumour's DNA can reveal mutations that particular drugs target. This is why some cancer treatments are now chosen based on the tumour's genetic profile rather than only where it started — a lung cancer with a certain mutation may be treated with a drug aimed precisely at it. This "targeted therapy" can be more effective and better tolerated than untargeted treatment, and genomic testing of tumours is increasingly routine.
Pharmacogenomics: predicting drug responses
Genes also influence how we handle medicines. Pharmacogenomics uses a person's genetic makeup to predict whether a drug will work for them, or whether they are at higher risk of side effects. Well-established examples include genetic tests before certain chemotherapy or immune-suppressing drugs to avoid dangerous toxicity, and variations that affect how people process common medicines. As this knowledge grows, checking relevant genes before prescribing certain drugs is expected to become more common, reducing trial-and-error and preventing harm.
The promise and the limits
The promise is more effective, better-targeted, less harmful treatment — and earlier, more precise diagnosis, including for rare inherited diseases where sequencing can end long diagnostic odysseys. The limits are real too. Most common diseases are shaped by many genes plus environment and lifestyle, so genetics rarely gives a simple answer; results can be uncertain or reveal unexpected findings; there are important questions about privacy, consent and equity of access; and a genetic risk is a probability, not a destiny. Precision medicine is a powerful and growing tool used where it genuinely adds value — not a replacement for the broader determinants of health.
In short
Key takeaways
- Precision medicine tailors prevention and treatment to the individual, increasingly using genetic information.
- In cancer, testing a tumour’s DNA can identify mutations that specific targeted drugs attack — treatment chosen by genetics, not just location.
- Pharmacogenomics uses a person’s genes to predict whether a drug will work or cause harm, reducing trial-and-error.
- It also helps diagnose rare inherited diseases that were previously hard to identify.
- Most common diseases involve many genes plus environment, so genetics informs rather than dictates — and raises privacy and equity questions.
Answers
Frequently asked questions
What is the difference between precision and personalised medicine?
The terms are largely used interchangeably. Both describe tailoring prevention and treatment to the individual using detailed information — increasingly genetic — rather than a one-size-fits-all approach.
How is genomics used in cancer treatment?
Testing a tumour’s DNA can reveal specific mutations driving the cancer. Some treatments (targeted therapies) are then chosen to attack those mutations, which can be more effective and better tolerated than untargeted treatment.
Does a genetic risk mean I will definitely get a disease?
No. For most common conditions, a genetic result is a probability influenced by many genes plus environment and lifestyle. It informs risk and choices but does not determine your future.
Sources
Where this is drawn from
- Genomics England / NHS Genomic Medicine Service
- NHS — Genomics and personalised medicine
- PHG Foundation / Nature — reviews of pharmacogenomics and precision medicine
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