Cancer care gets personal as tumor treatments are changing
May 17, 2018
In 2017, more than 1.7 million people were diagnosed with cancer in the United States, according to the National Institutes of Health.
Cancer can be difficult to treat, because each tumor is unique. Scientists are now gaining a better understanding of the changes that lead to cancer — and figuring out how to target them for personalized treatments.
"Cancer treatment is changing at a very fast pace," said Dr. Patricia M. LoRusso, an NIH-funded cancer treatment expert at Yale Cancer Center. "What somebody got a year ago may not necessarily be the same treatment recommended for another person today."
For decades, doctors have treated cancers based on where a tumor started, such as in the lung or colon. But often, a treatment that works well for one person doesn't work as well for another.
Research has revealed that each tumor has a unique combination of genetic changes. Cancer is caused by changes in genes that control the ways cells grow and survive. The cells begin to divide without stopping. They form growths called tumors, and some spread to other parts of the body.
The genetic changes that cause cancer are most often caused by exposure to sunlight, tobacco and other environmental factors that can damage genes. But some cancer-causing genes can also be hereditary.
These insights have led scientists to look for the unique genetic features of each person's tumor, then attack those specifically.
"Many times, we're trying to turn off certain pathways in the tumor that are activated and that cause it to continue to grow," LoRusso said. This type of treatment is called "targeted therapy," because the drugs target the specific changes in cancer cells that help them survive and spread.
Doctors can now send a sample of the tumor to a lab to identify important genetic changes. The doctor can then match the unique changes with treatments that are most likely to help.
"There are several drugs that are now on the market that have made a huge impact in the treatment of several types of cancer," LoRusso said.
Genetic testing isn't available yet for many types of cancer. NIH-funded studies are looking for ways to develop targeted therapies for more cancer types.
Another approach researchers are taking is to use a patient's own disease-fighting cells, called immune cells, to find and kill cancer cells. Scientists have successfully inserted cancer-fighting genes into a patient's immune cells, and two such therapies were recently approved by FDA.