President Barack Obama is requesting an increase of $215 million in the 2016 federal budget to launch the Precision Medicine Initiative. This boost in funding for research will give genetic causes of cancer a national focus specifically around precision or "personalized" treatments for cancer in the future.
Here are some facts about precision medicine:
1) What is precision or "personalized" medicine?
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 medicine makes diagnosis and treatment of cancer and other diseases more accurate, using 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 changes that drive their cancer. Then a treatment for a particular patient's cancer that best matches, or "targets," the culprit mutations in the tumor DNA is used. While such therapies are not widespread yet, many cancer specialists believe precision treatments will be central to the future of cancer care.
2) Do all patients receive precision or targeted treatment?
Not all patients need targeted therapy to treat their type of cancer. The use of targeted therapies is meant for patients whose tumors have specific gene mutations that can be blocked by available drug compounds. Patients who have mutations in certain types of genes, who have mutations that are beyond the reach of available drugs, or whose tumor cells lack identifiable mutations generally would not be candidates for personalized medicine treatments.
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) What is the precision medicine initiative at Dana-Farber?
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 of patients' tumors 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) What cancers have benefited from precision medicine research?
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 malfunctioning 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, small cell lung cancer, 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) What is the future of precision medicine?
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."
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