In January, the American Cancer Society reported the cancer death rate in the United States fell 2.2 percent from 2016 to 2017, the largest single-year drop ever reported. Although this exciting downturn is in part due to less tobacco usage, scientists also credit the development of targeted cancer treatments and immunotherapies in fighting cancer.
These therapies have been a turning point in cancer care, making treatments more precise for patients and often minimizing treatment side effects.
In the past, cancer was considered one disease, and so doctors treated all cancers similarly. Generally, doctors would surgically remove the cancer and then follow up with chemotherapy or radiation to kill any remaining cancer cells. These less precise follow-up treatments would often kill healthy cells as well. While some cancers are still treated with that regimen, much has changed in the way doctors approach the disease, which is now considered a group of diseases.
Personalized medicine is an evolving field in which doctors use diagnostic tests to identify specific biological markers, often genetic, that help determine which medical treatments and procedures will work best for each patient.
By identifying these markers and combining that information with other factors, such as a patient’s values and circumstances, doctors can develop more personalized treatment and prevention plans for their patients. As doctors become better at treating and preventing cancer, individualized health care will improve in quality, accessibility, and affordability for everyone.
Targeting specific cancers
The field began to take shape in the 1980s, when scientists discovered that the mutated HER2 gene could cause excessive cell division, encouraging cancer growth. Researchers discovered an antibody specific to HER2 that suppressed the growth of HER2-positive tumors.
That research led to breast cancer’s first targeted treatment, Herceptin (trastuzumab). The drug was approved by the U.S. Food and Drug Administration (FDA) for women with HER2-positive breast cancer in 1998. The FDA has now approved targeted therapies for 30 types of cancer, including those that originate in the blood, colon, and lungs.
In the last few years, the targeting methods of new cancer therapies have become even more individualized. In 2017, the first cell-based immunotherapy, Kymriah (tisagenlecleucel), was approved for the treatment of acute lymphoblastic leukemia. Kymriah is a customized treatment in which a patient’s T-cells, or lymphocytes, are collected, genetically modified, and then injected back into the patient with a new gene that provokes the T-cells to kill cancer cells.
Another breakthrough occurred with the 2018 approval of Vitrakvi (larotrectinib), which targets a genetic driver of cancer. For the first time, physicians can prescribe this targeted treatment based on a specific biomarker, regardless of where in the body the tumor is located. Vitrakvi is indicated for the treatment of adult and pediatric patients with solid tumors that have a specific gene fusion biomarker.
As researchers learn more about cancer cells and their drivers, matching patients with effective treatments will be more precise. Personalized medicine provides hope that individualized treatment will be more effective with fewer side effects than the old one-size-fits-all approach in treating cancer.