As Medicine Gets More Precise, Complexities Mount

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Doctors Speak Out

(December 06, 2013) — Once regarded as the “medicine of science fiction,” the idea of being able to personalize health care based on a person’s individual characteristics is now becoming reality.

This was the conclusion of a panel of experts at the latest Doctors Speak Out luncheon, held Tuesday, Dec. 3 at Georgetown University Medical Center (GUMC).

The topic, “This One’s for You: The Future of Precision Medicine,” inspired an energetic discussion of the future of this physician-driven, patient-centered approach. Denise Couture, producer for the nationally distributed public radio program The Diane Rehm Show, moderated the event, part of an ongoing quarterly series hosted by GUMC on topics across the health spectrum.

The Georgetown panelists were Michael B. Atkins, MD, deputy director of Georgetown Lombardi Comprehensive Cancer Center; Richard Schlegel, MD, PhD, academic chair of the department of pathology and director of the Center for Cellular Reprogramming; and Subha Madhavan, PhD, director of the Innovation Center for Biomedical Informatics.

Moving Away from ‘One Size Fits All’

Often referred to as personalized medicine, precision medicine means tailoring treatments to the individual characteristics of patients based on their genetic profile and their unique environmental influences. The mapping of the human genome nearly 15 years ago has opened up new research and treatment avenues that would never have been possible without this information.

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Doctors Speak Out

“The genomic revolution is allowing this paradigm shift away from a ‘one size fits all’ [approach to medicine],” Madhavan said.

In cancer, in particular, researchers are discovering myriad genetic mutations within tumors that might stimulate or inhibit their growth. One tumor could have hundreds of mutations that will influence how an individual might respond to treatment, according to Atkins.

“Occasionally we can find a dominant mutation … that is really responsible for driving that particular tumor. If we can identify that, and if we have a drug that can target that mutation, we can see the therapeutic benefits very quickly,” he said.

Atkins gave an example of a woman with a rare form of melanoma who was not responding to treatment. Her physicians at Georgetown analyzed the DNA sequence of her tumor and found a mutation that had not previously been reported in human cancers. However, a review of the literature found that same mutation in a blood cancer in a dog that responded very well to a particular drug.

The woman agreed to let her physicians try the therapy on her and, to everyone’s amazement, it worked.

“Her tumors literally melted away. She got up from the hospital bed in two days and was able to be discharged and within two weeks the tumors were barely detectable,” Atkins said.

Putting Data in its Context

While the concept of precision medicine is not entirely new, its incorporation into everyday medical practice is slow, as researchers and clinicians figure out how to apply the massive quantities of information that have been unlocked by the Human Genome Project.

According to Madhavan, an expert in bioinformatics, if all the data generated in the world today were housed on CD-ROMs, they would stack up from the earth to the moon and a quarter of the way back.

Thus, merely having information does not translate into high-quality, usable pieces of knowledge, the experts agreed.

“That’s where research comes in to take that information and try to apply it to patients,” says Atkins, an oncologist. “Many times data is not usable because there is not a defined mutation [in the gene], or there is not a drug yet to target that mutation, or there is just not enough information about how a set of changes in a tumor would influence response to available therapies.”

Without the right context and expertise, biomedical data can actually be harmful.

“In the wrong hands, data might encourage someone to use a therapy that is not appropriate for a given patient and might limit the patient’s ability to receive and respond to a more appropriate treatment. You really need a team of experts to interpret the information and optimally apply it to the management of an individual patient,” Atkins added.

Because it requires expertise to make sense of biomedical information, home genetic testing kits might create more confusion than consumers expect.

For example, knowing one has a genetic mutation that carries a higher risk of breast and ovarian cancer is not enough information to make a decision about what to do next. Genetic information must be coupled with family history, other health risks or mitigating factors, and an expert understanding of what this whole picture means for an individual.

The Georgetown Method

At Georgetown, researchers are advancing precision medicine through the use of the “Georgetown Method,” a new way of growing human cells in the laboratory that complements genetic analysis. Schlegel described the technique at the event.

By growing normal and tumor cells in the lab setting, for the first time researchers can screen for appropriate drugs that kill tumor cells while sparing normal cells.

“It is akin to looking for antibiotics that kill the bacteria but not the patient,” Schlegel explained. “There is a lot of potential for using this direct analysis of tumor cells and combining that with what we know about the genetics of these cells.”

The hope that underlies the pursuit of precision medicine is to spare patients from ineffective or sometimes harmful experimentation with different therapies. The ability to provide the right treatment for the right patient at the right time should be the goal of all health care practitioners, the experts agreed.

“The concept of this precision medicine fits very well into the Georgetown Jesuit model of cura personalis, in that we are focusing on health care with an emphasis on the unique person,” Schlegel said.

Georgetown University has filed a patent application for the cell culture technology mentioned here on which Schlegel and Xuefeng Liu are inventors; the patent currently is under exclusive option to a startup company, in which the University and Schlegel own equity, for commercial development. In addition, Georgetown and the University of Miami jointly have filed a patent application on related technology on which Schlegel is among the inventors.

The research described is funded partly by support from Georgetown University’s Department of Pathology. Other support is provided by
 the National Institutes of Health (R01 OD011168), the Department of Defense and the National Cancer Institute (P30-CA051008 and CA129003).

By Lauren Wolkoff, GUMC Communications