Question: My doctors have determined that my lung cancer is progressing on its current targeted therapy and want to do another biopsy. Why would I need another biopsy since we already know the biomarker type? If I do need another biopsy, should I consider a tissue biopsy or a liquid biopsy?

For people with lung cancer who have an identified driver mutation and who are experiencing progression on their current targeted therapy (TKI), it is important to re-biopsy the lung cancer to understand why the cancer has become resistant to the TKI. Understanding why your lung cancer has developed a resistance to your current treatment will help your care team choose the next best treatment for you.

For example, some drugs were developed specifically to be second or third line treatments to be given once the cancer has developed a resistance to the first line treatment. These drugs were designed to attack resistance mutations that cause progression and are often quite effective. The only way to know whether one of these drugs might work well for you is to re-biopsy your cancer to check for resistance mechanisms.

Liquid biopsies, or blood biopsies, may be used by some people experiencing progression because cancer sheds some of its tumor DNA into the blood which can be detected and tested in a blood specimen. A liquid biopsy is less invasive than a tissue biopsy, so it may be a good choice for many patients. However, some tumors do not shed their DNA into the blood, and in these cases a re-biopsy of the tissue may be necessary.

For more detailed information on your specific situation and what to discuss with your doctor, please contact GO2’s LungMatch team.

In each issue of Your Community, we will be answering your questions about lung cancer and/or GO2 programs and services, questions about screening, treatment types and advancements, clinical trials, support services, and the lung cancer community. To submit your question, please email it to yourcommunity@go2.org.

Please note that the information included in any published answers is for educational pursuit only and is not intended or implied to be a substitute for professional medical advice. The reader should always consult their healthcare provider to determine the appropriateness of the information for their own situation. Nothing from GO2 for Lung Cancer should be construed as an attempt to offer or render a medical opinion.