HealthMarch 16, 2020

A primer on precision medicine

By: Tayler Sindhu, MD
What is precision medicine? Learn how this developing field uses big data to inform clinical decision-making.

Advances in healthcare technology have changed medicine forever. Nearly all healthcare institutions are using electronic health records, patients are increasingly comfortable with health management apps and DNA sequencing has become faster and less expensive.

These and other technologies have resulted in large quantities of information—“big data”—that are ripe for analysis. This data has paved the way for an emerging field known as precision medicine, which focuses on creating a care plan built around a patient’s individual biology.

Rapidly advancing fields like biomedical informatics, genomics, proteomics and metabolomics all use big data to investigate the biological aspects of the processes that influence health. Precision medicine then uses these findings, which can include a patient’s genetics, protein interactions, metabolism and microbiome, to guide clinical decision-making.

The future of precision medicine

While not yet routinely incorporated into all aspects of clinical medicine, precision medicine has moved forward considerably in recent years. Former President Obama lent his support with the Precision Medicine Initiative of 2015, a $215 million investment aimed at finding “more and better treatments for cancer,” and the creation of All of Us, a program run by the National Institutes of Health that aims to collect clinical and genetic information from a large, diverse sample of the population.

This emerging approach has also led to the development of several promising new medications, especially in the field of oncology. Every tumor has a different genetic makeup, so cancer therapies have been developed that target specific subsets of tumors based on their genes and gene products. As Dr. Joel Diamond discusses in the Journal of Clinical Engineering, one such medication called larotrectinib inhibits specific types of cancer-driving proteins. These proteins result from a rare gene fusion found in some tumors.

The medication’s approval “marks another step in an important shift toward treating cancers based on their tumor genetics rather than their site of origin in the body,” said former Food and Drug Administration (FDA) commissioner Dr. Scott Gottlieb.

Hopeful developments have emerged outside the field of oncology, too. For example, elexacaftor-tezacaftor-ivacaftor, a breakthrough medication for patients with cystic fibrosis with a specific gene mutation (at least one Phe508 deletion), was approved by the FDA last year.

As Dr. Diamond notes, the increasing availability of genetic testing to patients is also a boon to precision medicine. For example, at-home colon cancer screening tests screen for blood products, DNA mutations (specifically KRAS mutations) and certain biomarkers that may be signs of precancerous lesions or colon cancer.

This genetic information may also become increasingly incorporated into clinical practice. Fields such as pharmacogenomics currently examine how a patient’s genetic makeup influences their response to certain medications, according to the Mayo Clinic. This information may help clinicians tailor medication choices and doses accordingly.

The challenges of precision medicine

While precision medicine has seen exciting successes and potential applications, some significant challenges come with it. For one, it relies heavily on tremendous quantities of data in addition to the information found in electronic health records; this additional data, which must be managed and interpreted, needs to be incorporated into clinical practice in a manner that avoids contributing “to current levels of fatigue and burnout” in medicine, as Dr. Diamond notes. Planning how to further incorporate precision medicine into clinical practice should focus on helping clinical decision-making and improving quality of care while also minimizing disruptions to clinician workflow.

Numerous other questions need to be addressed, including the difficulties of connecting genetic, metabolomic and proteomic data to clinical outcomes—by no means a straightforward process. How will this data be interpreted? Additionally, how will precision medicine affect healthcare disparities? Healthcare costs?

The use of protected health information is another major concern. The Precision Medicine Initiative highlighted the issue of privacy and data security, and the analysis of big data that drives precision medicine often involves large databases containing information from many patients. Maintaining the privacy of these patients is paramount, and thinking about how to do so raises bioethical issues about how such data should be handled and shared, given its inherently identifying nature. Addressing these issues in the future will be key.

Ultimately, while there are a number of undeniable challenges facing precision medicine as it develops, it offers a wealth of exciting possibilities for the future of patient care.

Tayler Sindhu, MD
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