Definition

Tumor Mutational Burden (TMB) is the measurement of the number of somatic mutations in tumor cells per megabase (mut/Mb) and is an independent biomarker that predicts response to immunotherapy. The FDA has approved pembrolizumab for unresectable or metastatic solid tumors with TMB-H (≥10 mut/Mb) status, regardless of cancer type.

Method

Next Generation Sequencing, Fragment Analysis, IHC

Accepted sample types

Solid Tumor, FFPE

Description

This test analyzes only tumor mutational burden.

Inheritance

This is an entirely somatic measurement; it quantifies the mutational burden in tumor tissue (or in ctDNA).

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

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Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

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VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

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How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

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Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

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