Precision Medicine: The Future Of Medical Treatment
This paper discusses the phenomenon that is precision medicine, which relies on tailoring the medicine to each patient’s needs. Precision medicine takes into account the molecular and genetic history of patients when tailoring the medication for them. This approach to health can benefit humans in decreasing side effects of medications and increasing life span. The articles I will present in this paper discuss many aspects of precision medicine, along with concrete examples demonstrating how and where it can be utilized. Moreover, I will mention the past and current advancements made in the field of precision medicine. The paper also makes a prediction about the future of precision medicine, taking into account different aspects, such as cost, availability, and disease type.
Introduction
The scientific community has always recognized that there exists a unique genetic and molecular makeup to each patient, which resulted in the invention of precision medicine. Precision medicine, also known as personalized medicine, is an evolving approach to disease treatment and prevention which considers patients’ individual characteristics — such as genetic history, molecular history, environment, and lifestyle — when presenting a treatment for the patient’s disease. The idea was first introduced in the late 1990s, but its applications are fairly new to the medical and scientific community. In this paper, I will explore the way precision medicine evolved into an effective application, and how it can further develop and become an alternative for traditional medicine.
Literature Review
In Pucheril & Sharma’s (2011) summary article that presented a thorough review of precision medicine, it is mentioned that the main ideas of precision medicine were available to the public since the 1960s. However, the term itself did not make its first official appearance until 1999. This was mainly supported by the scientific community’s complete discovery of the human genome, which is the complete set of nucleic acid sequence for humans which is encoded in the DNA. According to Wikipedia, the human genome project was officially finalized in April 2003, which aligns with the timeline of advancements in the field of precision medicine. Surprisingly, it was proven that mankind’s genetic makeup is 99. 1% identical, and only 0. 9% of the genes discovered in the genome account for the variances between different individuals. While this 0. 9% may seem like a trivial number, it has a rather substantial effect. This effect can be demonstrated in many ways, including the fact that various treatments work differently for different individuals. Despite the substantial difference between individuals’ reception of treatments, the scientific community still utilized an extremely broad approach to medical treatment. In traditional medicine, the treatment itself is more thoroughly considered than the patient. For example, once cancer chemotherapy has worked for a number of individuals, it is often deemed an effective approach to treat cancer for generally all cancer patients. In precision medicine, however, the patient is given as much thought — or even more — than the traditional treatment approach.
Advancements in Precision Medicine in the Past
In Pucheril & Sharma’s (2011) summary article, it is discussed that the progress that precision medicine had seen in the past was mainly due to two important discoveries. The first discovery is single nucleotide polymorphism (SNP) genotyping. In the article, they define SNPs as single nucleotide changed in the DNA sequence that appear frequently in the human population. They also account for more than 90% of currently known polymorphisms, which are essentially discontinues genetic variations resulting in the occurrence of several different forms of individuals of a population into many sharply distinct forms. These SNPs are imperative as they have been directly connected to patient susceptibility to multiple treatments and drug therapy responsiveness. Therefore, SNPs can a valuable tool in separating patients based on the way they may response to a certain drug or treatment method. The second discovery that largely contributed to precision medicine is microarray biochips. In their book that discusses biosensors, Li et al. , (2008) define biochips as microarray device that comprises three types: DNA microarray, protein microarray, and microfluidic chip. DNA microarray is especially important in this paper because it can perform large-scale and functional genomic analyses. Microarray biochips allowed precision medicine to progress because they have the ability to store and analyze a patient’s entire genome, thus allowing SNPs to work effectively and rapidly and providing researchers with a space to develop their protein-based therapeutics. Precision medicine has also been utilized in different aspects, such as genetic screening to predict the risk of passing potential genetic disorders to offspring. In their paper that examines the history and advancements of precision medicine, Phillips & Ginsburg (2018) illustrate the concept of genetic screening: at 8-12 weeks of pregnancy, a genetic testing that evaluates chromosomal abnormalities of the fetus can be performed. In addition, the entire genome can be sequenced at that time to rapidly diagnose any type of abnormal condition and, if possible, perform early treatments that reduce mortality. They supported their findings by a chart that displays the timeline of precision medicine applications across the normal lifespan.
Current Applications of Precision Medicine
In Pucheril & Sharma’s (2011) summary article, they inspect a recent case of successful precision medicine application that relates to human immunodeficiency virus (HIV). They mention that abacavir, an enzyme referred to as reverse transcriptase that is used to treat HIV, usually causes an unwanted reaction in patients that have been using it for six months. They cited another study conducted by Mallal et al. , (2002) where a potential link between the hypersensitivity that patients experience and allele HLA-B*57:01 (a variant of a gene) in the human genome. In the study, abacavir was only given for patients who were negative for HLA-B*57:01, and they displayed no sensitive reaction to the drug. They concluded that patients who carry the HLA-B*57:01 allele have a 60% chance of experiencing a hypersensitive reaction when treated with abacavir, as opposed to patients who do not carry the allele, who will not experience any type of negative reaction. This study was a breakthrough for the development of precision medicine as it proved that the patient’s genome can predict a response to drug therapy. The study was also extremely influential that it led the Food and Drug Administration and the European Medicines Agency to advise against using abacavir without prior testing for the HLA-B*57:01 allele. Not only can precision medicine help clinicians determine the type of drug to use for patients, but it can also assist them in regulating the dose of drug that they give to patients. For example, warfarin, a vitamin K antagonist, is often used as blood thinner. Warfarin is known for its narrow therapeutic range; adding more to the dose can lead to adverse bleeding, while decreasing the dose can lead to clotting. The difference in effects has been a mystery to clinicals for a long time, but precision medicine has begun decoding this mystery. Pucheril & Sharma (2011) cite another study that link the variation in three genes which can explain different reactions to warfarin, these genes are: CYP2C9, VKORC1, and CYP4F2. They also cite an analysis done by Borgiani et al. in 2009, which predict that different variations in the three genes mentioned above, along with other factors, is the reason for the 60. 5% dosing variability among patients. This study influenced a change in the warfarin US Food and Drug Administration label to include considerations of genetic differences between patients and has increased the number of research for more accurate dosage of warfarin. A final application of precision medicine that Pucheril & Sharma have stated is that it can predict the likelihood of contracting several illnesses. Infamous examples are mutations related to BRCA1 and BRCA2 genes, which have been previously linked to familial breast cancer. Another example is age-related macular degeneration (AMD), which has also been found to have a strong association with the CFH and ARMS2 genes. The advancements that precision medicine is currently making may soon allow for the development of genetic tests that can identify the existence of genes that are linked to specific illnesses and perform ophthalmologic screening to at-risk patients from an early phase of the disease.
The Future of Precision Medicine
In our current medical climate, precision medicine is shaping up to be the ideal method to tackle different diseases. The human genome research is the main foundation that can provide customized medical treatments to individual patients through incorporating genetics and molecular profiles and clinical characteristics in determining treatment method. According to Ginsburg and McCarthy, precision medicine intercrosses with the course of a patient’s disease at six important marks: predisposition, screening, diagnosis and prognosis, pharmacogenomics, and monitoring. Thus, precision medicine can be used to predict the likelihood of contracting certain diseases and therefore be used as an intervention tool. In 2015, former President Barack Obama made an announcement that the United States would launch a governmental precision medicine initiative, also known as All of Us initiative, that will include more than 1 million individuals. In this initiative, participants are expected to share the data gathered in a 10-year period about sequencing, medical records, and digital health technologies. This initiative will drive precision medicine to a new level with the availability of genetic and molecular information to analyze. As of now, the future of precision medicine looks extremely promising, although more research is crucial for its development.
Potential Limitations of Precision Medicine Growth
Notwithstanding the breakthroughs that were made in the area of precision medicine, it still has various limitations that may deter it from evolving. First, precision medicine can raise many ethical and legal issues. In All of Us initiative, for example, many participants’ health privacy will need to be invaded in order for researchers to acquire thorough information regarding their genetic and molecular makeup. For this reason, researchers have to undergo an extremely rigorous process to obtain informed consent. Cost is also another major issue that tands in the way of precision medicine development. In his article about SNPs, Carlson B (2008) mentions that SNP analysis revenues are estimated to be over $2. 2 billion by 2012, which reflects on the patients’ who may need them in treatment. Also, a report from the U. S. National Library of Medicine states that the All of Us initiative will cost many billions of dollars to uphold in the future, which will require congress approval over the next years. Additionally, technologies used in precision medicine, such as sequencing large amounts of DNA, and drugs that are tailored specifically for patients are currently expensive to carry out. However, a recent article by Facher L. (2018) demonstrates that the All of Us initiative reached participants, lower incomes, communities of color, and underrepresented populations in biomedical research. This is a great sign of precision medicine inclusivity and may lead to decreased prices in technologies that are currently rather expensive.
Conclusion
Since the term has been used for the first time in 1999, precision medicine has showed rapid growth both medically and socially. This paper introduced the history of precision medicine briefly and then the past and current advancements and applications that are being made in the area of precision medicine. Also, the paper discussed the potential future of precision medicine and predicated how its limitations may or may not prevent it from developing into become the default approach to medical treatment. Regardless of how hopeful precision medicine may be, there is still an immense amount of work and research that needs to be done in order for it to become the default medical approach.
References
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- Human Genome. Wikipedia. (2003) Retrieved from https://en. wikipedia. org/wiki/Human_Genome_Project
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- Carlson B. SNPs—A Shortcut to Personalized Medicine. Genetic Engineering & Biotechnology News. (2008) Retrieved from https://www. genengnews. com/magazine/94/snps-a-shortcut-to-personalized-medicine/
- What are some of the challenges facing precision medicine and the Precision Medicine Initiative. U. S. National Library of Medicine. (2019) Retrieved from https://ghr. nlm. nih. gov/primer/precisionmedicine/challenges
- Facher L. NIH opens nationwide enrollment for huge precision medicine initiative. STAT News. (2018) Retrieved from https://www. statnews. com/2018/05/01/nih-precision-medicine-all-of-us-enrollment/
