Healthcare has traditionally relied on treatment guidelines developed from the experiences of large groups of patients. These guidelines remain essential, but modern medicine is increasingly recognizing something equally important: two people with the same diagnosis may not respond to treatment in exactly the same way.
One patient may benefit greatly from a medicine while another experiences little improvement. A treatment that causes only mild side effects in one person may be difficult for someone else to tolerate. Differences in genetics, age, other medical conditions, medications, lifestyle, environment and even the biological characteristics of a disease can influence treatment decisions.
This is where personalized treatment, often referred to as precision medicine, becomes important.
For patients and caregivers, understanding this approach does not mean becoming experts in genetics or medical science. It means learning enough to participate meaningfully in conversations about treatment, ask informed questions and understand why a particular therapy may—or may not—be suitable for an individual patient.
What Does Personalized Treatment Actually Mean?
Personalized treatment is sometimes misunderstood as a completely unique medicine being created for every individual. In most situations, that is not what happens.
Instead, healthcare professionals use information about the patient and the disease to select from available prevention, diagnostic or treatment strategies.
The U.S. Food and Drug Administration describes precision medicine as an approach that considers differences in people's genes, environments and lifestyles when preventing or treating disease.[1] The National Cancer Institute similarly describes precision medicine as using information about a person's genes, proteins, environment and lifestyle to help prevent, diagnose or treat disease.[2]
Personalization can therefore involve many different pieces of information.
A doctor may consider the patient's age, kidney or liver function, previous treatments, allergies, other illnesses, medicines already being taken, family medical history, lifestyle and personal treatment goals. In some diseases, laboratory testing may provide additional information about genes, proteins or other biological markers.
The result is not necessarily a radically different treatment. Sometimes personalization simply means selecting the most appropriate medicine, dose or combination of therapies for that particular patient.
Biomarkers Are Changing Some Treatment Decisions
One of the most visible examples of personalized medicine can be found in cancer care.
Historically, cancers were mainly classified according to where they originated—for example, breast, lung or colorectal cancer. Modern testing has shown that cancers developing in the same organ can have different biological characteristics.
Biomarkers are genes, proteins or other substances that can provide information about a disease. According to the National Cancer Institute, biomarker testing may help doctors identify treatments that are more likely to work for particular cancers. Some targeted therapies and immunotherapies are effective only when specific biomarkers are present.[3]
This helps explain why two people diagnosed with what appears to be the same type of cancer may eventually receive different treatments.
However, patients should also understand the limitations.
Finding a genetic alteration or biomarker does not automatically mean that an effective targeted treatment exists. Some test results identify changes whose significance is still uncertain. In other situations, a potentially relevant therapy may only be available through a clinical trial.
Personalized treatment therefore does not remove uncertainty from medicine. It provides healthcare teams with additional information that can sometimes make treatment selection more precise.
Tumor Testing and Inherited Genetic Testing Are Not the Same
This distinction can be particularly important for patients and families.
A tumor may develop genetic changes during a person's lifetime. Testing those changes can sometimes help doctors understand the cancer and identify possible treatments. These are commonly called somatic changes and, in most cases, they are not inherited by children.
Testing for an inherited or germline genetic variant is different. It examines genetic changes that a person was born with and which may sometimes have implications for other family members.
The National Cancer Institute advises that genetic counselling can help people understand the potential benefits, limitations and implications of testing for inherited cancer risk.[4]
For families, this is especially important because genetic information can occasionally raise questions extending beyond the person receiving treatment. A result might have implications for siblings, children or other relatives.
Patients should therefore ask their healthcare team exactly what type of genetic or molecular test is being recommended, what information it may provide and whether the findings could have relevance for family members.
Genetics Can Also Influence How Medicines Work
Personalized medicine extends beyond cancer.
Pharmacogenetics or pharmacogenomics examines how genetic differences can influence the way a person responds to certain medicines.
Some people metabolize particular drugs more quickly or slowly than others. Genetic variation may sometimes affect the dose required, the likelihood of benefit or the risk of adverse effects.
The FDA notes that pharmacogenetic information, when considered alongside other clinical information, can sometimes help healthcare professionals determine treatment strategies, appropriate dosing or the likelihood of benefit or toxicity.[5] Pharmacogenomic information is also included in the labeling of a number of medicines.[6]
This does not mean everyone requires genetic testing before receiving medication. Whether a pharmacogenetic test is useful depends on the particular medicine, medical condition and clinical circumstances.
Patients should therefore be cautious about interpreting direct-to-consumer genetic reports independently or changing medication because of information found online. Results need appropriate clinical interpretation.
The Patient Is More Than a Test Result
One of the most important principles of personalized treatment is also one of the easiest to overlook: personalized medicine should be about the whole person, not merely their DNA.
Two patients with similar laboratory findings may have completely different priorities.
One may want the most intensive treatment available despite significant side effects. Another may prioritize maintaining independence, continuing employment or reducing hospital visits. An older person living alone may face challenges that are very different from those of someone surrounded by a large support network.
Financial circumstances, travel requirements, fertility concerns, caregiving responsibilities and quality-of-life considerations may all affect what constitutes a reasonable treatment choice.
This is why shared decision-making has become an important part of patient-centred healthcare.
The U.S. Agency for Healthcare Research and Quality defines shared decision-making as a collaborative process in which patients and clinicians make healthcare decisions using medical evidence, professional expertise and the patient's own values, preferences, goals and circumstances. Caregivers and family members can also have an important role.[7]
Personalization therefore involves both science and conversation.
What Patients Should Ask Their Healthcare Team
Medical consultations can be stressful, particularly after a serious diagnosis. Patients frequently remember only part of what was discussed. Preparing questions beforehand can make the conversation more productive.
Useful questions may include:
- What treatment options are available for my condition?
- Why are you recommending this particular treatment for me?
- Are there tests that could help determine which treatment is more likely to work?
- What are the expected benefits and possible side effects?
- Are there alternatives?
- How will we know whether the treatment is working?
- Could my other illnesses or medications affect this treatment?
- Would genetic or biomarker testing provide useful information?
- If a genetic test is recommended, is it testing my disease, an inherited condition, or both?
- Would the result affect members of my family?
- Is a clinical trial relevant to my situation?
- What happens if the first treatment does not work?
Patients do not need to ask every question at a single appointment. Complex treatment decisions may require several discussions.
The Caregiver's Role Can Be Extremely Valuable
A caregiver may be a spouse, child, parent, relative, friend or another trusted person. Their contribution can become particularly important when patients are tired, anxious or undergoing complicated treatment.
Caregivers can help maintain an updated list of medicines, organize reports, record appointments and write down questions. With the patient's permission, they can attend consultations and take notes.
They can also notice practical issues that may not be obvious during a short hospital visit: changes in appetite, mobility, sleep, mood, medication adherence or the patient's ability to manage normal daily activities.
However, personalized healthcare also requires respect for the patient's voice. Caregivers can support decision-making without replacing the patient's preferences whenever the patient is able to participate.
One helpful approach is for the caregiver to ask the patient before appointments: “What matters most to you about this treatment?”
The answer may provide the medical team with information that no laboratory test can reveal.
Keeping Medical Information Organised
Personalized care depends on good information.
Patients moving between hospitals or consulting multiple specialists should try to maintain an organized medical record containing relevant diagnoses, pathology reports, imaging reports, laboratory results, previous treatment details, medication lists and known allergies.
Where genetic, genomic or biomarker testing has been performed, keeping the complete laboratory report can be particularly helpful. A simple statement that a test was “positive” or “negative” may not contain enough information for another specialist to interpret the result.
Family health history can also matter. The CDC notes that family medical history can help healthcare professionals understand disease risk and determine whether particular screening or genetic counselling may be appropriate.[8]
Digital records have made information easier to store, but patients should also think about privacy. Genomic information can be especially sensitive. The World Health Organization has emphasized responsible governance, transparency, privacy, equity and protection of individual rights in the collection and use of human genomic data.[9]
Before agreeing to extensive genomic testing, patients can reasonably ask who will have access to the data, how it will be stored and whether it may be used for research.
Clinical Trials May Sometimes Be Part of the Discussion
Precision medicine is developing rapidly, and not every promising approach has yet become standard treatment.
Clinical trials test new methods of preventing, diagnosing or treating disease. Some modern trials use genetic or biomarker information to determine whether a person may be eligible to participate.
Participation is always voluntary and requires informed consent. Eligibility also depends on specific criteria, and an experimental treatment is not guaranteed to be better than standard care.
Patients interested in research should discuss the possibility with their treating doctor and understand the potential benefits, risks, additional tests, travel requirements and time commitment involved. NIH resources also encourage potential participants to discuss clinical research with their physicians and study teams before deciding whether to participate.[10]
Personalized Does Not Automatically Mean Better
The language surrounding precision medicine can sometimes create unrealistic expectations.
A newer test is not automatically more useful than an established test. A treatment described as “targeted” is not automatically safer. Genetic information may sometimes produce uncertain findings rather than a clear treatment recommendation.
Cost and availability also vary considerably between countries, healthcare systems and medical centres. Sophisticated testing has little value when the result will not meaningfully change treatment.
Patients can therefore ask a very practical question before undergoing a test:
“How could the result change what we do next?”
If the medical team can explain how different possible results would influence treatment, the reason for testing becomes much clearer.
Learning Without Becoming Overwhelmed
Patients and caregivers today have access to an enormous quantity of health information. Unfortunately, reliable medical guidance sits alongside advertising, personal testimonials and unsupported claims.
A sensible starting point is to use information from recognised hospitals, government health agencies, universities, professional medical organisations and peer-reviewed research.
Online information can help patients formulate questions, but it should not replace a clinician who understands the complete medical situation.
It is also perfectly reasonable to ask for explanations in simpler language. Terms such as mutation, biomarker, genomic sequencing, targeted therapy and pharmacogenomics may be routine for medical professionals but completely unfamiliar to patients encountering them for the first time.
Understanding should be part of treatment—not an optional extra.
Moving Towards More Individualised Care
Personalized treatment represents an important change in the way healthcare is evolving. Instead of asking only, “What treatment is normally used for this disease?”, medicine can increasingly ask, “What treatment is most appropriate for this disease in this particular person?”
The answer may come partly from laboratory testing, partly from medical history and partly from understanding the patient's own priorities.
Technology will undoubtedly expand what healthcare professionals can measure. Genomic sequencing, molecular diagnostics, digital health information and increasingly sophisticated clinical tools may provide doctors with more detailed information than ever before.
But information alone does not create good healthcare.
The most effective personalized care still depends on something fundamentally human: informed conversations between patients, caregivers and healthcare professionals.
A patient who understands the purpose of a test, knows the realistic treatment choices, asks questions and communicates what matters most is better equipped to participate in those decisions.
Personalized medicine, at its best, is therefore not simply about finding the right molecular target. It is about using the best available evidence while remembering the individual person behind every medical record.
References and Sources
1. U.S. Food and Drug Administration (FDA). Precision Medicine. The FDA describes precision medicine as tailoring prevention and treatment according to differences including genetics, environment and lifestyle.
2. National Cancer Institute (NCI). Definition of Precision Medicine — NCI Dictionary of Cancer Terms.
3. National Cancer Institute (NCI). Biomarker Testing for Cancer Treatment. Information on molecular profiling, biomarkers, targeted treatments, immunotherapy and the limitations of biomarker testing.
4. National Cancer Institute (NCI). Genetic Testing Fact Sheet and The Genetics of Cancer. Guidance regarding inherited genetic testing, genetic counselling and interpretation of test results.
5. U.S. Food and Drug Administration (FDA). Table of Pharmacogenetic Associations. Information on how genetic variation may influence drug metabolism, therapeutic response, dosing and adverse effects.
6. U.S. Food and Drug Administration (FDA). Table of Pharmacogenomic Biomarkers in Drug Labeling.
7. Agency for Healthcare Research and Quality (AHRQ). About Shared Decision Making and The SHARE Approach. Guidance on patients, clinicians and caregivers working together when considering healthcare options.
8. Centers for Disease Control and Prevention (CDC). About Family Health History and Precision Health: Predict and Prevent Disease. Information regarding family history, disease risk, screening and genetic counselling.
9. World Health Organization (WHO). Guidance for Human Genome Data Collection, Access, Use and Sharing. Published November 20, 2024. Guidance addressing ethics, transparency, equity, genomic-data governance and individual rights.
10. U.S. National Institutes of Health (NIH). Clinical Studies: Information for Patients and Potential Volunteers and related NIH clinical-trial resources. Information on voluntary participation, informed consent, eligibility and discussions with healthcare professionals.
Medical Disclaimer
This article is intended for general educational and awareness purposes only. It should not be used as a substitute for medical advice, diagnosis or treatment from a qualified healthcare professional. Decisions regarding genetic testing, biomarker testing, medicines or other treatments should be made in consultation with an appropriately qualified healthcare team.