Precision Medicine: What Is It, Who Offers It?


In the age of genomics, gene sequencing and DNA research, there is an ever-expanding body of knowledge on how cancer and heredity are interrelated. Now there is a name to go with the practice of using genetic testing that diagnoses and treats conditions: precision medicine.
Precision medicine or personalized medicine is a medical practice that involves utilizing genetic testing as a method to consider particular treatments and/or medications to address a cancer diagnosis. Ideally, precision medicine is the "custom-fit" suit of cancer care compared to an "off-the-rack" option. When a person is diagnosed with cancer, medication treatments are prescribed taking into consideration how a particular gene responds to a medication.
Several hospitals across the country have started precision medicine programs to support this expanding field. In November 2013, Dana-Farber Cancer Institute, Brigham and Women's Hospital and the Broad Institute of MIT and Harvard collaborated to establish the Joint Center for Cancer Precision Medicine. The Center combines DNA sequencing, tumor molecular profiling technologies and computerized tumor re-creation to enhance cancer care.
"This center will allow us to be optimally positioned to answer the big questions in cancer genetics, especially as they affect clinical decision-making," explained Levi Garraway, MD, PhD, an associated professor of medicine at the Dana-Farber Cancer Institute and director of the center.
In addition to determining what tumor types respond to a medication, precision medicine also aims to study why some patients become resistant to particular medications or why a tumor may not respond to a particular treatment. For example, colon cancer patients with a mutation in their KRAS gene are not likely to respond to treatments with cetuximab (Erbitux) or panitumumab (Vectibix) for cancer care.
"We are plumbing the depths of what genetic mutations in tumor actually cause the tumors and, in some cases, which cause resistance to current chemotherapy," says Dr. Stephen G Emerson, PhD, the Director of the Herbert Irving Comprehensive Cancer Center at New York-Presbyterian/Columbia University Medical Center in a press release describing its precision medicine program. 
Precision Medicine and Cancer Prevention
In addition to guiding cancer treatments, cancer physicians also see the potential for precision medicine to guide preventive efforts. By discovering what genes put a patient at greater risk -- as the BRCA-1 and BRCA-2 genes have been linked with increased risk for breast cancer.
Other examples of hospitals offering precision medicine programs include New York-Presbyterian Hospital and the Rutgers Cancer Institute of New Jersey. Dr. Lorna Rodriguez is a Rutgers chief of gynecologic oncology who has studied CD44 cell surface receptors in patients with ovarian and breast cancers. By studying how the presence of CD44 receptors affect treatment approaches, a physician is better able to anticipate how a disease my spread  and what treatments are better able to effectively treat a condition. Today, this is similar to how an infectious disease physician looks at a type of bacteria and determines the most appropriate antibiotic for killing the bacteria.

Though it is a growing field, personalized medicine has already experienced several successes. This includes the approval of a medication known as imatinib (Gleevec), which inhibits the growth of an enzyme found in patients with chronic myelogenous leukemia.