Definition

The TOP2A gene is located at 17q21-22, close to the HER2 gene, and encodes topoisomerase II-alpha, the main target of anthracycline-class chemotherapeutics. TOP2A co-amplification is seen in approximately 35% of HER2-amplified breast cancers; independent of HER2 amplification, this co-amplification is a clinically useful marker that predicts response to anthracycline-based neoadjuvant chemotherapy (pathological complete response 30% versus 11%).

Method

FISH analysis

Accepted sample types

Fresh tumor tissue, FFPE

Description

Response to drug treatment, anthracyclines.

Inheritance

This is a somatic tumor genetic change.

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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