Personalized medicine, also known as precision medicine, is redefining healthcare by tailoring medical treatment to the unique characteristics of each individual. This approach integrates genetic, environmental, and lifestyle factors to enhance disease prevention, diagnosis, and treatment. The potential benefits of precision medicine are profound, and include numerous foundations and applications which we will explore in this piece. It must be noted, however, that the implementation of personalized medicine also presents significant ethical, economic, and logistical challenges that must be addressed to ensure equitable and effective care for all.
Genomics: The Foundation of Personalization
At the heart of personalized medicine lies genomics. As the cost of genome sequencing continues to decline, integrating genetic testing into routine clinical practice is becoming increasingly feasible. Advances in genomics, bioinformatics, artificial intelligence (AI), and data analytics now allow us to identify genetic variations that influence disease susceptibility and drug response.
Pharmacogenomics: Personalizing Treatment Through Genetics
One of the most transformative applications is pharmacogenomics (PGx)—the study of how genes affect an individual’s response to medications. By understanding genetic differences that influence drug metabolism, transport, binding receptors, efficacy, and toxicity, clinicians can tailor treatments to individual patients, reducing trial-and-error prescribing and minimizing adverse drug reactions. This approach is particularly impactful in oncology, psychiatry, and cardiology, where drug responses vary widely. A 2018 U.S. study estimated that preventable adverse drug reactions (ADRs) and events (ADEs) due to inappropriate medication alert overrides cost the healthcare system between $871 million and $1.8 billion annually.
There are many ways we can apply PGx in everyday medical practice. For instance, genetic testing for liver enzymes such as CYP2D6 and CYP2C19 can identify patients who may not respond to common antidepressants. As approximately 60% of the 700,000 people who die by suicide each year have a mood disorder such as depression or bipolar disorder, we can understand the critical importance of PGx testing in improving mental health treatment and outcomes.
Additionally, PGx is pivotal in optimizing Clopidogrel therapy, an antiplatelet medication, by analyzing variations in the CYP2C19 gene. Individuals with certain genetic variants are classified as intermediate or poor metabolizers, meaning they convert less of the prodrug into its active form. This reduced activation significantly increases the risk of adverse cardiovascular events, such as stroke or heart attack, highlighting the life-saving potential of personalized treatment strategies. Despite its promise, the integration of pharmacogenomics into clinical practice faces hurdles, including high testing costs, limited clinician training, and concerns about genetic data privacy. Nonetheless, the potential of PGx to enhance drug safety and efficacy is undeniable.
Artificial Intelligence: Powering Precision
We have seen the revolution of AI in all aspects of technology, including healthcare. AI is rapidly transforming the field of personalized medicine by enabling the analysis of complex datasets—including genomic, lifestyle, and clinical information—to predict disease risks and guide treatment. AI tools are now used to forecast conditions such as diabetes, Alzheimer’s disease, and cardiovascular disease, allowing for earlier and more precise interventions.
By leveraging data from electronic health records, genetic profiles, and wearable devices, AI enhances diagnostic accuracy and enables highly customized treatment plans. However, challenges remain, including concerns about data privacy, algorithmic bias, and the interpretability of AI-driven decisions.
Polygenic Risk Scores
In the era of information technology, clinicians and scientists have developed an additional key tool in precision medicine—Polygenic Risk Scores (PRS). These scores aggregate data from multiple genetic variants to estimate an individual’s risk for complex diseases such as coronary artery disease or breast cancer. Increasingly, PRS are being used to guide screening and preventive strategies, enabling a more proactive and personalized approach to healthcare.
Nutrigenomics: Personalized Nutrition
Another application of personalized medicine is nutrigenomics, where we explore how genes interact with nutrients, offering a new frontier in personalized health. By analyzing an individual’s genetic profile, nutrigenomics enables the creation of tailored nutrition plans that optimize health, prevent disease, and enhance wellbeing. For example, some individuals may have genetic variants that affect fat metabolism, vitamin absorption, or caffeine sensitivity. Personalized dietary recommendations based on this information can help reduce the risk of chronic conditions such as obesity, diabetes, and cardiovascular disease. While still an emerging field, nutrigenomics holds great promise for the future of preventive medicine.
Cancer Care Through Precision Medicine
Cancer treatment has entered a new era, driven by the power of personalized medicine. Unlike traditional approaches that apply the same treatment to all patients with a particular cancer type, personalized oncology customizes therapies based on an individual’s genetic makeup, tumor biology, and molecular markers. Personalized medicine is not just changing how we treat cancer—it’s transforming how we understand it. By aligning treatment with the unique biology of each patient, we move closer to a future where cancer care is more precise, more effective, and more humane.
For instance, in non-small cell lung cancer (NSCLC)—which accounts for approximately 85% of all lung cancers—patients with mutations in the epidermal growth factor receptor (EGFR) gene can benefit from targeted therapies such as osimertinib. This drug specifically blocks the abnormal signaling pathways that fuel tumor growth, offering a more effective and less toxic alternative to conventional chemotherapy. Similarly, individuals with inherited mutations in the BRCA1 or BRCA2 genes—both essential for DNA repair—are at significantly higher risk for breast and ovarian cancers. Genetic testing enables these individuals to pursue enhanced screening, preventive strategies, or prophylactic treatments, potentially detecting cancer at an earlier, more treatable stage—or even preventing it altogether.
However, the complexity of cancer remains a formidable challenge. Tumors are highly heterogeneous and can evolve over time, often developing resistance to initially effective therapies. This dynamic nature demands continuous monitoring, adaptive treatment plans, and a strong commitment to ongoing research and innovation.
Patient-Derived Therapy
Mesenchymal stem cell (MSC) and microfragmented fat tissue (MFAT) therapies
are also considered forms of personalized medicine—particularly when they utilize the patient’s own biological material. Mesenchymal stem cells (MSCs) have demonstrated notable clinical efficiency in a wide range of regenerative medicine applications, supported by both preclinical and clinical studies. On the other hand, MFAT therapy involves harvesting a patient’s adipose (fat) tissue through a minimally invasive procedure. This tissue is then processed and re-injected into targeted areas of injury or degeneration—such as joints, tendons, or ligaments—based on the patient’s specific clinical condition. MFAT is rich in adipose-derived stem cells, growth factors, and anti-inflammatory agents, all of which support tissue repair and regeneration in a way that aligns with the patient’s unique biology.
Despite the challenges, the potential of personalized medicine to revolutionize healthcare is undeniable. It offers a future where treatments are more effective, side effects are minimized, and diseases are detected before they become life-threatening. Realizing this vision requires investment in research, education, and infrastructure, as well as a commitment to addressing the ethical and social implications of this evolving field. With thoughtful planning, inclusive policies, and ethical practice, personalized medicine can become a cornerstone of 21st-century healthcare, delivering on the promise of truly individualized care.
About Professor Dragan Primorac, M.D., Ph.D
Professor Dragan Primorac, M.D., Ph.D., is a pediatrician, geneticist, forensic expert witness, founder of the St. Catherine Specialty Hospital, and co-founder of the International Society of Applied Biological Sciences (ISABS). A pioneer in applying DNA technology to identify mass grave victims, Primorac helped establish international standards in clinical and forensic genetics. Prof. Primorac has authored nearly 300 scientific papers and 30 books and book chapters, including the recently published Pharmacogenetics in Clinical Practice (Springer Nature), and was ranked among the top 2% of global scientists by Elsevier for career impact.
