Tumor Mutational Burden

Video Transcript

All the DNA needed to make every human body part is housed in each cell. DNA provides a unique code of genetic information that is made up of a particular sequence of units called bases. The order and position of these bases determine the specific proteins that are created, which allows every cell in the human body to grow and function normally.


Cancer is caused by mutations, or changes, in the DNA of a person’s cells. When the DNA code is changed, the encoded protein could be made incorrectly and might not be able to function properly, losing its protective function or driving cells to grow and divide out of control, causing cancer. Once a person is diagnosed with cancer, their doctor must collect as much information as possible about the specific mutations causing their cancer.


Next-generation sequencing (NGS) is a test that performs a comprehensive analysis of a person’s DNA code. Tumor Mutational Burden (TMB) refers to the number of mutations or changes to the DNA code present in a cancer cell. The more changes present, the higher the cell’s tumor mutational burden. TMB is measured on a scale to categorize it from low to very high.


Knowing a tumor’s TMB can be useful in predicting how cancer will respond to specific treatments like immunotherapy. For instance, cancer cells can present signals on their surface, which are targets for immune cells to find and attack. There are more of these signals for the immune system to detect tumors with a high TMB. Immunotherapy drugs help alert the immune system to identify these signals and kill cancer cells.

At Caris, we perform next-generation sequencing and can measure a tumor’s mutational burden. This information allows oncologists to provide their patients with a catered treatment plan. Ask your doctor about Caris’s testing today.

Patient Education Videos

The Central Principles of Molecular Biology video series is meant to help explain molecular profiling and cancer, so that you can understand how Caris molecular profiling helps fight cancer through precision oncology.