When President Barack Obama rolled out his Precision Medicine Initiative, it included an increased funding request of $215 million in the 2016 federal budget. Precision medicine is changing the way cancer is studied and treated. Here are five important things to know about it.
1. Precision medicine can improve diagnosis and treatment
Physicians have long recognized that the same disease can behave differently from one patient to another, and that there is no one-size-fits-all treatment. Precision cancer medicine makes diagnosis of cancer and other diseases more accurate, and evaluates the specific genetic makeup of patients (and, in cancer, of their tumors) to select the safest and most effective treatments for them. In cancer, precision medicine involves testing DNA from patients’ tumors to identify the mutations or other genetic changes that drive their cancer. Physicians then may be able to select a treatment for a particular patient’s cancer that best matches, or “targets,” the culprit mutations in the tumor DNA. While such therapies are not widespread yet, many cancer specialists believe precision treatments will be central to the future of cancer care.
2. Not all cancer patients can or should receive precision medicine
Targeted therapies may be appropriate for patients whose tumors have specific gene mutations that can be blocked by available drug compounds. These therapies aren’t indicated for patients whose tumors are driven by mutations that can’t be targeted by available drugs or which lack identifiable “driver” mutations.
According to the National Cancer Institute, a patient is a candidate for a targeted therapy only if he or she meets specific criteria, which vary depending on the disease. These criteria are set by the Federal Drug Administration (FDA) when it approves a specific targeted therapy.
3. Profile is one example of precision medicine in action
The Profile project, launched in 2011 at Dana-Farber Cancer Institute and Brigham and Women’s Hospital, is an example of precision medicine at work. All adult patients diagnosed with cancer can consent to have samples of their tumors analyzed for the presence of mutations and other cancer-related DNA abnormalities.
“We’re really excited about Profile because it represents our first foray into using molecular techniques, rather than anatomical criteria, to understand cancers” said William Hahn, MD, PhD, deputy chief scientific officer at Dana-Farber. “With all of the knowledge we’ve gained over the last 30 or 40 years about what makes cancers tick, we can now try to get at the basics of that within the DNA of a tumor.”
Since the inception of Profile, more than 10,000 genetic profiles – the particular set of mutations that drive a tumor — have been completed, and 400 profiles are added each month to the database. Profile testing recently expanded to pediatric patients at Boston Children’s Hospital.
4. Several cancers are already benefitting from precision medicine treatments
Ten years ago, researchers at Dana-Farber and in Japan published a study showing that non-small cell lung cancer patients whose tumors had a mutated version of a protein called Epidermal Growth Factor Receptor (EGFR) responded dramatically to a drug that specifically targets the EGFR protein.
“Prior to this research, lung cancer treatment had not made much progress,” says Bruce Johnson, MD, chief clinical research officer at Dana-Farber, who co-led the 2004 study with colleagues Pasi Jänne, MD, PhD, Matthew Meyerson, MD, PhD, and William Sellers, MD (now of the Novartis Institutes for BioMedical Research). “Today, patients with EGFR mutations who are treated with targeted drugs have a year of remission and survive an average of two to three years, with some making it to five years or more.”
Besides lung cancer, Dana-Farber researchers have made precision cancer discoveries in triple-negative and HER2-positive breast cancer, colorectal cancer, neuroblastoma and other malignancies.
Clinicians at Dana-Farber/Brigham and Women’s Cancer Center currently use targeted therapies that pinpoint genetic mutations in a select number of other cancers, including kidney, leukemia and sarcoma.
5. Researchers are working on expanding precision medicine treatments
New research in precision medicine is now focused on identifying a far greater number of mutations for a wider array of cancers, ultimately enabling clinicians to treat more cancers with targeted therapies in the future.
Dana-Farber, Brigham and Women’s Hospital, Boston Children’s Hospital, and the Broad Institute of MIT and Harvard formed the Joint Center for Precision Cancer Medicine. The collaboration seeks to create “precision medicine pathways” for patients with advanced cancers and to speed the development of personalized therapies.
“This center allows us to be optimally positioned to answer the big questions in cancer genetics, especially as they affect clinical decision-making,” said Levi Garraway, MD, PhD, associate professor of medicine at Dana-Farber and the center’s director. “We seek to understand which genetic and other molecular alterations predict how tumors will respond to targeted drugs, why some patients become resistant to drugs, and what that means about the treatments that should be tried next.”