When scientists sequenced the human genome, researchers believed that the breakthrough would be the key to unraveling human diseases and would spur a cascade of cures. They were wrong—or at least premature: The connection between our genes and our risk for disease has proven to be more complicated.
Scientists discovered that it isn’t just our genes but also their interaction with each other and our environment that make us sick, and that interaction provides clues to help us recover. This ongoing effort has been labeled precision medicine.
Precision medicine, for example, gives doctors the chance to skip intrusive biopsies in favor of quick blood tests, to personalize lifestyle recommendations based on the bacteria that live in our guts and to prescribe cancer treatments that leverage our own immune system against the disease. President Barack Obama pledged $215 million in 2014 to fund a precision-medicine initiative.
Precision medicine might have the buzz, but it isn’t the only frontier of medical breakthroughs. Innovations expand existing treatment options and create possibilities, such as making diabetics’ insulin therapy as easy to take as it is to breathe and using cardiac catheterization techniques to blast away blood clots in new ways.
The cost of genetic tests dropped dramatically over the past decade, and their use is applied in almost every field of medicine. It cost $2.7 billion in 1991 for the first human sequencing—the technique that allows researchers to read and decipher a person’s genetic information. Now a patient can get his/her full genetic sequence deciphered for about $1,000. We sequence newborn babies’ genes to detect genetic dangers. We sequence cancers to match tumors to treatments and sequence viruses to find mutations in new strains of disease.
The Eyes Have It
Despite the dramatic drop in testing expenses, cost is the chief challenge for these advances. Understanding disease at the molecular level requires specialized equipment as well as the employment and training of those who operate the equipment. As we’re better able to understand diseases and treat them individually, medication costs rise. Insurance coverage for new medications is undetermined.
That said, other breakthroughs ultimately will replace costlier procedures. Some innovations just hit the consumer market; others still are in the laboratory. Many fall somewhere in between. A few might never be available at the local pharmacy, but they all reflect a sea change in thinking about disease and its treatments.
GOODBYE, BIOPSIES. As tumors grow, they shed cells into the host’s body and leave a trail that can be picked out against the background of a patient’s DNA. Researchers are looking to that trail to design tests that could replace the need for painful biopsies for tumors like those that are found in colon and prostate cancers. So instead of surgically taking tissue samples from tumors, doctors might be able to screen for cancers in a blood test within the next 3–5 years.
Before chemotherapy or immunotherapy is prescribed, most cancers are biopsied and evaluated to determine the biological processes that went awry within a specific tumor, which is an example of precision medicine. Using a so-called liquid biopsy means that this important information can be gleaned from just a blood test. These blood tests already are used for advanced cancers that have spread and for lung cancer, where performing biopsies can be dangerous. Testing this way can be repeated often, and it allows doctors to get early and ongoing markers of efficacy and see to what extent that a treatment changes a tumor’s DNA, says Dr. Victor Velculescu of Johns Hopkins University’s Kimmel Cancer Center.
Patients who are in remission also will benefit, because such tests can detect whether lingering cancer cells are becoming active again before a patient might find a tumor or have other symptoms of recurrence.