Last updated – 20 Jan 2021
What does Tumor Mutation Burden ‘TMB’ mean to me?
This is the total number of mutations (DNA mistakes) that are found in the cancer cells of a biopsy sample. ie the density of the burden.
Knowing the actual tumor mutational burden can help your medical team plan the best treatment action. In recent times it has been acknowledged that tumors containing a high number of mutations respond better to certain types of immunotherapy (Check Point Inhibitor) Tumor mutational burden is a type of biomarker called TMB. [Origin]
Check Point Inhibitors – research
- PD1/PD-L1 pathway (program death ligand)
- MSi-High (Microsatellite High)
Descriptions of TMB
- TMB was studied both as a tiered variable (low ≤5 mutations/Mb, intermediate >5 and <20, high ≥20 and <50, and very high ≥50)” [Origin]
- The TMB is defined as the total number of nonsynonymous mutations per coding area of a tumor genome. [Origin]
- TMB of a tumor sample is calculated by the number of non-synonymous somatic mutations (single nucleotide variants and small insertions/deletions) per mega-base in coding regions. 21 TMB represents both the stability level of the tumor genome and heterogeneity of the tumor micro-environment. [Origin]
Discusses the relationship of High TMB and Checkpoint Biomarkers in relation to immunotherapies