Human–Genome Sequencing Moves Personalized Medicine Closer to Reality for Mesothelioma Patients
By Nancy Meredith
When researchers on the U.S. Human Genome Project completed mapping the entire spectrum of genetic materials that can be found in humans, they moved medicine beyond the traditional trial-and-error method of treating and diagnosing diseases to an approach where a person’s genetic makeup can be used to tailor their medical care. Patient-centric treatment optimizes the potential for success of a patient’s care by offering the right treatment at the right time. This is especially vital for mesothelioma patients and other seriously ill patients where misdiagnosis, ineffective treatments and side effects can leave the patients and their doctors frustrated with the inability to bring relief.
Mesothelioma, an aggressive asbestos-caused cancer can be treated with varying degrees of success through surgery, radiation and chemotherapy. Currently there is no known cure for mesothelioma, and the average survival time varies from 4 – 18 months after diagnosis. Scientists in the area of genetic research continue to pursue an effective detection method, treatment, or cure for mesothelioma and other cancers. In a study of nuclear receptor genes in lung tumor tissue conducted by University of Texas Southwestern Medical Center, for example, the co-authors said that when looking at genetic signatures they hope to predict how well a patient will respond to treatment as well as leading the physician to the best treatment for that individual.
DNA Testing Leads to New Prescription for Twins Struggling with Rare Disease
Most recently, physicians were able to move DNA testing out of the lab and put it to practical use in one of “the first examples of using genome sequencing to directly benefit a patient rather than just to study the causes of disease.” NPR reported that 14-year-old twins from California had struggled their whole lives with debilitating symptoms of dopa-responsive dystonia, a neurological disorder that causes muscles to spasm and twist.
However, when the treatments stopped working their mother took them to Houston’s Baylor College of Medicine to the Baylor Human Genome Sequencing Center. There the team of researchers found the twins had a different genetic mutation than was typical of the disease. Based on those findings, the doctors were able to develop a new serotonin-producing medication offering a personalized approach to treating the teens. They are now active and are running on their school’s track team.
Personalized care targeted to a patient’s unique characteristics and genetic makeup optimizes the potential for success of the treatment and offers treatment options that may not otherwise have been considered. Just as with diseases such as what the twins struggled with, mesothelioma treatments can differ dramatically across patients and personalized treatment targeted to a particular patient is most often successful.
Genetic Discoveries Made Daily
An article in the July/August issue of AARP Magazine offers further proof that genetic testing can make the difference in the quality of life for patients suffering debilitating illnesses. A man in Baltimore suffered uncontrollable bouts of vomiting and diarrhea that left him weak and dehydrated, yet doctors could not pinpoint the underlying disease. After being in and out of the hospital over several years, and being subjected to extensive testing, a DNA test at Massachusetts General Hospital found the man had a genetic marker pointing to celiac disease – a relatively easily treated disorder. In this case, the DNA test was able to diagnose the disease when other “standard” tests failed.
According to Daniel Kastner, MD, PhD, scientific director at the National Human Genome Research Institute, patients and physicians alike are beginning to see benefit from human-genome sequencing. He says that virtually every week a new discovery is made, adding “keeping up with this deluge of new information is like trying to drink from a fire hose.”
Since the symptoms of many diseases are often confused with other conditions, knowing a patient’s genetic makeup, as well as history and context, can help in the diagnosis. For the man with celiac disease physicians had not asked about his diet, and in the case of mesothelioma, knowing that a patient had been exposed to asbestos in the past can speed the diagnosis.
What About Cost?
People struggling to find a diagnosis or relief from a persistent illness are often faced with huge medical bills already. However, many patients say they will pay even more if it means finding an answer to their illness. Dr. James Lupski, Baylor’s vice chairman of genetics believes that these patients, and more like them, will begin to drive demand while the price of personal genome mapping falls.
NPR reports that just a year ago, the cost to discover the key to the twins’ sickness cost about $30,000 each to sequence the genomes, plus another $40,000 in computer and specialist analysis. Now, an uncomplicated genome sequencing can cost just $8,000. Many experts also believe the price may continue to drop to less than $1,000 in a few more years, making it affordable to many patients.
National Institutes of Health Director Dr. Francis Collins said that the application of mapping with the twins is “the leading edge of what will become, pretty soon, a deluge of such reports.”
