By Pat Carragher - December 30, 2020
Getting diagnostic tests for cancer is never fun. Getting biopsies for lung cancer in particular can be uncomfortable and stressful, but thanks to a recent approval by the U.S. Food and Drug Administration, the genetic testing necessary to look for mutations driving cancer growth has become quicker and easier.
In August, the FDA approved a liquid biopsy test that also uses next-generation sequencing technology to identify patients with specific types of mutations in non-small cell lung cancer (NSCLC).
The test involves a simple blood draw and results are known in about a week. A bronchoscopy or a CT-guided biopsy had been the most traditional ways of checking for NSCLC. The former involves running a tube down a patient’s throat and into the lungs. While the procedure doesn’t usually hurt, it can be uncomfortable and sometimes last 30 minutes or longer.
“A liquid biopsy is looking for DNA that is shed from the cancer cells in the blood stream,” said Dr. Bruna Pellini, a thoracic oncologist at Moffitt Cancer Center. “So you don’t have to go through a bronchoscopy or a CT scan to find the lesion, to then biopsy it. It’s less invasive. You just have to get a blood draw and then we’ll try to find the cancer cells’ DNA in the blood.”
The liquid biopsy tests have been available to Moffitt patients for a few years. The FDA approval means that more insurance providers can cover the cost of testing. In addition to being more convenient, the turnaround for results is significantly quicker.
“It takes about five to seven days for us to get the results,” Pellini said. “For the traditional biopsy we have to count the timing between the ordering, the procedure scheduling and completion, in addition to the time that the biopsy sample has to be processed and analyzed. It may take two to three, sometimes even four weeks for us to have results.”
The quicker turnaround not only means that patients will know their results sooner, but more importantly doctors can start their treatment plans sooner.
“Patients get very anxious and the cancer may grow in that time we’re waiting,” Pellini said. “The sooner you know, the sooner you can act and start treatment.”
While liquid biopsies are quicker and easier, they are not as sensitive as the tissue biopsy, according to Pellini.
“If you find a mutation that is driving cancer growth, you can start treatment,” Pellini said. “You may still need to do a tissue biopsy if you have a high suspicion that a patient has a mutation that is driving their cancer growth.”