In what is still considered a fairly recent breakthrough, genetic testing has not only come into the market, but has seen drastic advances in efficiency, accuracy and, of course, cost since its introduction. With the emergence of more targeted genetic analysis, the healthcare industry has also seen the rise of personalized medicine. While the technology behind whole genome sequencing continues to improve, it's advancing so quickly that other modalities are struggling to keep up, especially when it comes to sorting out the information delivered by the technique.
As physicians have learned more about their patients' DNA, new drugs have been developed that treat diseases at the molecular level. The combination and subsequent pairing of these techniques has led to the incorporation of pharmacogenetics and pharmacogenomics into personalized medicine. In an interview with ADVANCE, Shelly Gunn, MD, PhD, chief medical officer at MolecularHealth, discussed the impact of this new dimension to modern medicine.
"The study of pharmacogenetics and pharmacogenomics is becoming bigger and broader and much more personalized for each patient in that we now not only can look at their inherited genetic profile," said Gunn. "But we actually can look at the tumor genome profile and choose a growing number of targeted therapies."
Gunn referred to the combination technique as "bench to bedside" or "translational" genomics, meaning pharmacogenetics and pharmacogenomics are still largely utilized in a research capacity, but have started being introduced in clinical laboratory environments to meet a growing demand. By analyzing the molecular reactions of patients with diseases like cancer or physical symptoms like a tumor, physicians are able to determine the effectiveness of a drug. For patients, the technique ensures the prescribed drugs will not only work in terms of treating the disease or disorder, but also that their body will react well to that treatment.
"It's really been amazing how new a concept that is to a lot of my colleagues and a lot of people in the field - that we really are dealing with two different genomes here," continued Gunn. "And we can give a drug that, on paper, should do a spectacular job at addressing a genomic aberration in a tumor, only to find that we've created an adverse event for the patient because we didn't bother to look at their germ line genome to see how they would metabolize that drug."
Each patient has a large, specific genome that reacts to treatments, therapies and drugs differently depending on their genetic predispositions. In the case of cancer patients or patients with tumors, not only do physicians have to account for their personal genome, but they also have to examine the genome of the cancer cells or tumor tissue as well. This distinction is the reason certain drug combinations should theoretically work without harming a patient on paper, but sometimes end up having unintended consequences in practice. Although terms like "pharmacogenetics" and "pharmacogenomics" come across as synonyms, more or less, Gunn clarified the difference.
"Those of us in oncology like to talk about the patient's inherited genome and the study of that genome and how it responds to and metabolizes drugs as pharmacogenetics," explained Gunn. "If we're talking about the tumor genome and what the target of therapy is, we tend to talk about pharmacogenomics."
Although the constantly increasing efficiency in next-generation sequencing, the ability to compute and organize the information of a patient's entire genome is still somewhat lacking in comparison. Gunn noted the gap in technology, describing it as one of the main reasons pharmacogenetics and pharmacogenomics aren't used more widely in clinical applications. She also pointed out the added quantity of data produced by analyzing two different genomes in a single person, essentially doubling the amount of information to sort through.
"That is the biggest limitation right now, where we know this is the best way to approach giving a drug," said Gunn. "But because of all the issues involved with access to the technology and access - processing the data - it's very limited right now in clinical use."
Regardless of the present state of analytical technology, it is progressing -- despite a comparatively slower speed. By utilizing pharmacogenetics and pharmacogenomics, physicians are able to make decisions based on treatment options they can predict will most positively impact the patient. As these techniques continue to be utilized in more and more clinical cases, the need for improved data processing becomes greater.
Genetic sequencing options stand as the tool of the future. The ability to match the right drug to the best possible outcomes in terms of a patient's biological response is key in the treatment of diseases such as cancer. The growing role of pharmacogenetics and pharmacogenomics in the clinical environment raises questions and concerns regarding the state of bioinformatics in the healthcare industry, but the continued improvement of these technologies leaves room for optimism.
Michael Jones is on staff at ADVANCE.