Introduction

With more people being affected by illnesses every day, there is now a pressing need to provide solutions that are more targeted versus the usual one-size-fits-all approach. Thankfully, with the current advancement of technology and healthcare, precision medicine has become more accessible to the public than ever. The goal of precision medicine is to provide effective and tailor-made therapeutics that take into account the patient’s unique lifestyle, environment, and even genetic makeup (What Is Precision Medicine?: MedlinePlus Genetics, n.d.). This revolutionizes conventional therapies that have been shown to be less and less successful throughout the years due to numerous factors (e.g., continuous increase of genetic diversity, clinical trials for approving conventional therapies often have localized respondents thereby neglecting more specific criteria, etc.).

In this article, we will discuss precision medicine, its prospects, and how healthcare benefits from this advancement. We will also be briefly tackling precision diagnostics, a branch of precision medicine that utilizes the latest computational tools and technologies.

Precision Medicine vs. Precision Diagnostics

Precision medicine is an emerging branch of healthcare that aims to treat and prevent diseases with the consideration of the individual’s genetic variability, environment, as well as lifestyle (What Is Precision Medicine?: MedlinePlus Genetics, n.d.). The issue with current therapeutics is not every patient will respond to a certain treatment in the same way. While a type of drug may work for one person, this may not be true for another; some may even suffer unexpected side effects. Thus, the approach of precision medicine allows healthcare experts to carefully predict and curate treatment options that would work best for a select group of people (What Is Precision Medicine?: MedlinePlus Genetics, n.d.), with these groups being specific to having a certain gene, for example.

While “precision medicine” may be a relatively new term, it has already been applied to numerous areas in healthcare and disease. Here are some examples of precision medicine in action according to the Learn.Genetics website of the University of Utah (More Examples of Precision Medicine in Action, n.d.):

• Pharmacogenomics. Pharmacogenomics is a branch of genomics that considers the patient’s genetic variations to determine how they will respond to a certain drug. In this practice, healthcare professionals are able to prescribe drugs that are tailored to the individual based on their unique genomic makeup, thereby providing more effective treatment. Potentially, this approach could also lift the patient’s burden of any additional expenses on ineffective drugs while also preventing them from experiencing harmful side effects.
• Genomics and cancer. Cancer cells usually arise via unwanted genetic changes, otherwise known as mutations. Genomics experts are able to pinpoint and compare unique genetic profiles of cancer cells to normal cells which help to determine the origin and molecular characteristics of these cells. Thus, this information is useful in developing a more precise treatment plan to manage, and hopefully, kill the cancer. 
• Regenerative medicine. One way precision medicine is applied in regenerative medicine is through the utilization of stem cells. Stem cells are unspecialized cells, meaning they do not yet possess a specific role or function (versus, for example, liver cells, skin cells, eye cells, etc.). In regenerative medicine, a patient’s own stem cells can be used and engineered into a specific tissue and taken back into the patient for repair. An advantage of this approach is that the chances of the immune system rejecting the new tissue are lowered due to the cells originating from the patient, thereby encouraging effective tissue regeneration.   
• Obtaining molecular profiles of microbes. With the current advancement of sequencing technologies, doctors are now able to apply precision medicine tools to identify pathogens affecting patients and consequently provide appropriate treatment strategies. In addition, with regards to patients afflicted with viruses, molecular tests are able to determine the strain of the virus which allows health practitioners to select more targeted drugs versus those that are known to be resistant to the particular strain.
• Personalized diets. Precision medicine can also be translated to the food we eat. Nutrigenomics is a relatively new research area that determines how an individual’s genetic variations affect how the body responds to certain nutrients. While the science is in its early stage, an increasing number of people take these genetic tests and consult a nutrigenomics expert for a personalized diet and lifestyle plan, depending on their genetic makeup. This allows them to maximize the nutrients from their planned meals as well as incorporate more efficient exercise routines into their everyday lives, thus improving their overall well-being. (If you want to learn more about nutrigenomics, we have two dedicated articles to this exciting field! Click here to access the two articles: Nutrigenomics: The Link Between Disease, Diet, and Our Genes; The Varying Applications of Nutrigenomics)

Precision diagnostics, on the other hand, is one branch of precision medicine that deals with the use of molecular tests, sequencing, and/or omics strategies to accurately identify a patient’s ailment or disease. Data from omics approaches are also used to curate a precise healthcare or treatment plan for the patient (Brown & Elenitoba-Johnson, 2020).

This specific branch of precision medicine utilizes the latest advancements in technology such as multi-omics approaches, artificial intelligence (e.g., convolutional neural networks, etc.), as well as next-generation sequencing (NGS) in order to make more accurate diagnoses of diseases.

Some examples of techniques in precision diagnostics are the following:

• DNA Sequencing. Genomic and genetic sequencing techniques are often used for cancer patients. One example is whole genome sequencing (WGS), which provides a more holistic background of the cancer patient and, in turn, can determine the most optimal clinical trials that may be suitable for them (Rusch et al., 2018).
• RNA Sequencing. While DNA sequencing may be more holistic and offers a generalized view of a patient’s disease prognosis, RNA sequencing delivers a more targeted and advanced approach. In light of vague cancer diagnoses, RNA-Seq can aid in providing a more molecularly detailed diagnosis via cell trajectory analysis which gives information on a patient’s background as well as the specific subtype of the cancer; ultimately, this helps in developing the patient’s unique treatment plan (Rusch et al., 2018). In addition, analyzing a patient’s transcriptome allows for a clearer view as well as a more individualized prognosis of the disease, especially for malignant cancer (Westermann & Vogel, 2018).
• Proteomics. Omics approaches – apart from transcriptomics – have been commonly used in precision medicine. Studying proteins that are relevant to a particular disease is also one of the most viable approaches in precision diagnostics. These proteins in question have undergone post-transcriptional modifications that allow them to have specialized functions in some diseases (Aebersold & Mann, 2003). Profiling these proteins via the combination of mass spectrometry and computational tools (e.g., bioinformatics, etc.) provides associations of these specialized proteins to particular diseases, thereby enhancing precise diagnoses (Aebersold & Mann, 2003).

Thus, precision diagnostics today mainly utilizes computational tools, omics approaches, and big data. Even US tech companies such as the International Business Machines Corporation (IBM) have recently been involved in the field of precision diagnostics, with the aim to help solve medical problems while being able to generate vast amounts of high-quality data (Precision Diagnostics | IBM Research, n.d.). One of IBM’s projects involves microfluidic technologies (systems or devices that allow control of precise, minute volumes of fluids), that are important for procedures such as mass spectrometry, and ultimately, for use in point-of-care diagnostics (Precision Diagnostics | IBM Research, n.d.).

Precision Medicine: Principles and Concepts

As mentioned previously, precision medicine came about to combat the issues surrounding drugs or treatment options that are a one-size-fits-all approach. This is one of the main reasons why precision medicine is often referred to as “personalized medicine”, given that it takes into account genetic variations as well as other external factors that were discussed (i.e., lifestyle, environment, etc.). However, the term “personalized medicine” does not necessarily imply that a drug or therapeutic is developed for a single individual. Rather, according to Naithani et al. (2021), it is targeted to populations that are known to be susceptible to a particular disease or are found to respond similarly to a specific drug (Naithani et al., 2021).

It is also important to note that precision medicine is heavily associated with modern tools and technologies, namely:

• Omics approaches. Recent advances and optimization in technology enabled quick improvements in research utilizing genomics, epigenomics, transcriptomics, proteomics, metabolomics, and even microbiomics.
• Big data. Big data becomes all the more relevant in this day and age. These are large, and continually expansive datasets that mainly pertain to health, disease, and biological information from patients that range from biomarkers (i.e., clinical- and omics-based) to laboratory and radiological investigations.
• Artificial Intelligence (AI) and machine learning. AI tools such as machine learning are then used to analyze these data (i.e., big data) via complex flowcharts that generate an algorithm for the management of specific populations with a target disease.
• Pharmaco-omics. Pharmaco-omics or pharmacogenomics has also been crucial for the advancement of precision medicine, especially with the creation of new drugs that are more targeted to a particular population that differs in their susceptibility to developing a disease or their response to a certain medication. This practice prevents these drugs from being prescribed to non-responders, avoiding the occurrence of harmful effects, as well as proving to be more cost-efficient in the long run.

These tools are combined with external factors (i.e., environmental, social) as well as preventive and population medicine in order to guide decisions on treatment and/or management of the disease for the target population (Naithani et al., 2021).

Overall, the goal of precision medicine is to offer patients treatment options that are specific to their biological and clinical characteristics. What precision medicine does is it determines which treatment or management strategies are best suited to which population depending on the group they belong to (with these groups being distinguished based on their biological attributes) (Delpierre & Lefèvre, 2023).

Genetics and genomics in precision diagnostics

As previously discussed, precision medicine (and precision diagnostics) utilizes large volumes of biological and clinical data mostly obtained through omics approaches (Delpierre & Lefèvre, 2023). In traditional healthcare, especially in the Philippines, experts still mainly rely on visual inspection to make diagnoses of patients’ diseases. However, genomics and genetics approaches have the capacity to reveal the root cause of diseases by looking at the patient’s genes and/or genome, especially for rare diseases (Reshaping Diagnostics with Genomics & Precision Medicine, n.d.).

Genetics is the study of genes and therefore, the inheritance of certain traits or conditions. Genomics, on the other hand, is the study of a person’s entire collection of genes, otherwise known as the genome (Genetics vs. Genomics Fact Sheet, n.d.). How are these, then, used in precision diagnostics?

Genomics is currently one of the main technologies that help advance precision medicine, and it does so via Next-generation sequencing or NGS. The power of NGS lies in its ability to sequence large numbers of genes or even the entire genome in a short amount of time (Qin, 2019). According to Illumina, genomic profiling using NGS can drastically improve outcomes for those afflicted with cancer with only a single biopsy or test used. Genomics also helps in understanding the roots of undiagnosed rare diseases as well as spearhead research in pharmacogenomics (which we will get more into later) (Precision Genomics | Value of NGS in Precision Medicine, n.d.).

There are numerous benefits to using genomics via NGS in precision diagnostics such as:

• discovering gene variants associated with specific diseases
• diagnosing rare diseases
• helping in matching patients to specific treatments and overall,
• reducing the expenses paid for treatment and management. (Precision Genomics | Value of NGS in Precision Medicine, n.d.)

With the advent of today’s technology, whole genome sequencing has become more accessible in the clinical setting both in terms of cost and availability, while also having turnaround times as short as seven to ten days. Furthermore, disease management that is clinical genetics-based has also been practiced more due to the emergence of more targeted therapies especially in the area of oncology (Crabtree & Miele, 2022).

According to an article by Crabtree et. al (2022), in the realm of cancer, precision diagnostics has given clinicians the ability to “predict, prevent, and personalize” by doing the following:

• screening and assessing whether patients have the risk of developing cancer
• finding and categorizing tumors
• making predictions on patients’ prognoses
• selecting available targeted therapies for specific patients and
• observing the burden of the disease on the patient for the long term

These new healthcare approaches for cancer are further advanced with research in genomics and genetics, leading to a new era of disease management that is individualized to the person’s genes, the type of tumor, and its clinical presentation (Crabtree & Miele, 2022).

Pharmacogenomics

Another commonly observed concept in precision medicine is pharmacogenomics. Dissecting the name, pharmaco- implies the study of drugs or pharmacology, while -genomics, as mentioned, is the study of the genome. Combining these two together, pharmacogenomics is the study and practice of developing drugs tailored to individuals based on their genetic makeup (as some drugs are safer and more effective for people with certain genes and vice versa) (What Is Pharmacogenomics?: MedlinePlus Genetics, n.d.). In other words, pharmacogenomics looks at the interactions between drugs and genes (Reshaping Diagnostics with Genomics & Precision Medicine, n.d.).

In precision medicine, pharmacogenomics studies the effects of an individual’s genetic polymorphisms (i.e., gene variants) on the response and state of the drug being given (Naithani et al., 2021). In addition, it has two major roles in precision medicine, namely:

1. to lead pharmaceutical companies toward drug discovery and development based on specific population subgroups (e.g., those who share a genetic polymorphism that responds well to a particular drug) and
2. to steer physicians into selecting appropriate and targeted drugs for patients based on their genetic makeup thereby avoiding adverse reactions and optimizing efficacy by prescribing the correct dosage.

Typically, testing gene variants that influence a patient’s drug response is performed the same way gene variants associated with diseases are being tested. This is done by first determining genetic loci that are already associated with known drug responses, and then assessing individuals that have no known responses. Some examples of these approaches include multigene analysis and using whole-genome single nucleotide polymorphism (SNP) profiles (Pharmacogenomics and Personalized Medicine | Learn Science at Scitable, n.d.).

Today, pharmacogenomics is gradually being introduced into conventional treatment strategies for select patients. For example, if an association is made between a gene variant and a drug response, clinicians can make decisions based on the patient’s genomic information and either adjust the drug’s dosage or choose a totally different drug as necessary (Pharmacogenomics and Personalized Medicine | Learn Science at Scitable, n.d.).

Consumer Diagnostics

From the previous topics, it is safe to assume that precision medicine would not exist without diagnostics. Currently, genetic testing – a type of diagnostics tool – has been commonly used alongside other precision medicine approaches. Genetic testing is a type of medical test that aims to observe and pinpoint any alterations in a patient’s genes (e.g., changes in a nucleotide, a single gene, or the entire genome), chromosomes (e.g., duplicate or extra copies of chromosomes), as well as proteins (e.g., changes in the number of proteins, etc.). Results from these tests would then inform the patient if they have increased risks of developing and/or passing on a certain disease (What Is Genetic Testing?: MedlinePlus Genetics, n.d.).

Consumer diagnostics in healthcare pertain to solutions that adhere to a direct-to-consumer approach in hopes of delivering accurate and immediate health disease diagnosis and are usually done remotely. This field in healthcare is continuously being advanced by genetic testing and DNA research, along with the present technology of AI (Direct-to-Consumer Tests | FDA, n.d.). Some consumer health diagnostics are the following:

• blood-based
• microbiome analysis
• diagnostic support bots powered by AI
• mobile imaging, etc.

These various solutions each provide information on an individual’s disease risk or may reveal genetic roots of disorders that may have not yet manifested (Direct-to-Consumer Tests | FDA, n.d.).

One of the most popular companies that offer consumer diagnostics is 23andMe which specializes in genetic testing services. Generally, their genetic reports would only require saliva samples, thus being non-invasive. These samples are then sent to their laboratory and analyzed by their own group of scientists and medical professionals. Once analysis is complete, a comprehensive DNA report will be sent back to the consumer which contains information about their ancestry or health-related insights (e.g., health predisposition, gene carrier status, wellness, etc.) depending on the kit being availed (How Does 23andMe Work: DNA Test Instructions & Reporting, n.d.).

One advanced example of consumer diagnostics being utilized today is through the use of AI-based mobile image analysis. In a study by Mannino et al. (2018), the researchers introduced a smartphone application that is able to detect anemia in an individual using only photos of their fingernail bed. The app analyzes the color and metadata of the fingernail and correlates the results to screen the individual with anemia (Mannino et al., 2018). This innovative tool therefore provides a non-invasive tool to monitor anemia at any given time. Other applications of AI-based image analysis include bettering prediction of disease risk and diagnosis of diseases such as retinopathy (caused by diabetes), cancer metastasis, and screening for benign melanoma (Johnson et al., 2021).

Conclusion

Precision medicine is a growing field in healthcare that continues to make a difference in patient outcomes for various diseases. It is essential that further research in precision medicine is carried out to facilitate improved accuracy in the diagnosis of diseases, to make better clinical decisions in terms of a patient’s treatment or management strategies, as well as to provide an avenue for drug discovery and development that are targeted to specific subpopulations.

As more research work is done on omics approaches while also utilizing the technological power of AI and developing better data handling and storage approaches, precision medicine will eventually integrate with today’s advancements and hopefully become a staple in conventional healthcare.

However, this also entails the cooperation of all parties involved in the science, namely researchers, medical and health professionals, as well as the stakeholders that aim to support the precision medicine initiative. Thus, it is also crucial to bring more awareness to the studies and advances of genomics and genetics as a whole in order to form a more comprehensive idea of precision medicine, the genetic disorders it aims to tackle, and the potential products and services that are to be made accessible to the public in hopes of delivering a more efficient and inclusive means of healthcare.

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