Understanding Precision Medicine
Traditional chemotherapy drugs are designed to target rapidly dividing cells in the body. These drugs can eliminate cancer, but they can also harm healthy cells.
Drug therapies are evolving though — thanks, in part, to doctors with the Froedtert & the Medical College of Wisconsin Cancer Network.
Cancer drugs are increasingly able to target the specific characteristics that make cancer cells cancerous in an approach called precision medicine.
“The idea behind precision medicine is to identify a weakness in the cancer cell and design a treatment specifically targeting that vulnerability,” said Ben George, MD, medical oncologist and MCW faculty member. “We can maximize the effect on the tumor and minimize damage to the normal cells.”
Most precision drugs target one of the many genetic changes that cause a normal cell to become cancerous. Precision drugs also target proteins that have changed due to abnormalities.
"For example, some breast cancers express a protein called HER2/neu," Dr. George said. "Patients with this tend to do worse than others. Now, an antibody drug conjugate called fam-trastuzumab deruxtecan-nxki (links chemotherapy to a targeted anti-cancer drug) precisely targets this protein, and outcomes can be very good."
The Rare Cancer and Precision Medicine Clinic brings together a team of doctors who have particular expertise in evaluating the molecular alterations associated with tumors. The team works in tandem with doctors from the Cancer Network’s disease-specific programs when patients with rare or advanced cancers need more options. These specialists apply precision medicine therapies as appropriate, along with more traditional treatment approaches individualized to each patient.
As needed, patients are discussed in a molecular tumor board where a team of precision medicine experts, including genomicists, medical oncologists and molecular pathologists, makes recommendations.
“We look systematically at the plethora of genomic changes that may be present in a tumor,” Dr. George said. “We then discuss the best strategies for targeting those specific alterations.”
As academic researchers, team members are often able to give patients access to newer drugs and innovative therapies. The Cancer Network has the largest cancer clinical trials treatment program in Wisconsin.
“We have several precision medicine trials open,” Dr. George said. “Patients with molecular alterations who do not qualify for standard therapies may be candidates for additional options through these trials.
The number of patients who can benefit from precision medicine is growing. Already, precision medicine treatments are offered through many cancer programs in our Cancer Network. For example, advanced melanoma is an aggressive type of skin cancer that previously had limited treatment options. Now, doctors can extend survival for patients with this disease using targeted therapy and immunotherapy, both precision medicine treatments.
”We are beginning to recognize that precision medicine strategies can be applied with dramatic impact not only to patients with advanced or rare cancers, but also to those with early-stage tumors,” Dr. George said. According to Dr. George, advances in artificial intelligence and large-scale genomic testing will lead to an explosion of options for treating cancer with precision medicine.
“As our computational capabilities become more sophisticated, our ability to understand the vulnerabilities of a tumor will improve exponentially,” Dr. George said. “That will open up endless therapeutic possibilities. Ultimately, we will be able to deliver more effective treatments — even for people who had limited options before.”