HER2 FISH for Equivocal Cases Test Cost & Procedure

What is the HER2 gene?

Human epidermal growth factor receptor 2 is a protein that is encoded by the HER2 gene (HER2). On the surface of some breast cancer cells are HER2 proteins. When they are active, they give instructions to breast cancer cells to multiply and develop.

Normal regulation and control of breast cell growth is provided by HER2 proteins. But, when the HER2 gene is changed, which happens in roughly 1 in every 5 cases of breast cancer, an excessive number of HER2 proteins are produced. Breast cells begin to grow and divide too quickly as a result.

Is testing for HER2 required?

HER2-positive breast tumours usually exhibit increased levels of aggressiveness. They are also more likely to happen again. Fortunately, HER2 targetting medications are widely accessible. These drugs work quite effectively in treating this type of breast cancer.

If you have breast cancer, you need to know if it is HER2-positive or HER2-negative. It's important to have the tests that prove this. The outcome is very significant in terms of your prognosis and available treatments.

the exams IHC and FISH

To determine if your breast cancer is HER2-positive, your doctor will advise testing on a tissue sample.

Immunohistochemistry and in situ hybridization (ISH or FISH) are the two test modalities approved for the diagnosis of HER2 (IHC).

Tests for in situ hybridization (ISH or FISH)

The results of an in situ hybridization (ISH) test, which examines the sample's genetic composition, might be either affirmative, negative, or equivocal. When a result is unclear, more investigation is required. The term "fluorescence in situ hybridization" refers to an ISH test (FISH).

Sometimes IHC tests come first. However, if IHC testing is inconclusive, an ISH test should be performed. An ISH test can frequently tell if a tumour is HER2-positive or HER2-negative.

Immunohistochemical tests (IHC)

Immunohistochemistry (IHC) assays are used to assess whether breast cancer cells contain an excessive amount of HER2 protein receptors. Your doctor will interpret this test as follows:

• A 0 is an unfavourable score.
• Likewise, a score of 1+ is unfavourable.
• A score of 2 or above is considered unclear (uncertain).
• A result of 3 or higher is favourable.

Takeaway

If you have recently been diagnosed with breast cancer, your doctor will likely request a number of tests in order to better understand the condition and choose the most appropriate course of action. These tests should include a HER2 test.

Make certain you are familiar with all the outcomes prior to starting treatment. If your breast cancer has returned after being treated, discuss with your doctor whether a HER2 test is necessary.u