Skip Ribbon Commands
Skip to main content
Menu

INTERPHASE FLUORESCENCE IN SITU HYBRIDIZATION TEST FOR BREAST CANCER TISSUES, GASTRIC/GASTRO-OESOPHAGEAL JUNCTION CARCINOMAS (GEJ) USING HER2 (ERBB2) DNA PROBE

Synonym(s):

FISH HER2

Lab Section Category

Cytogenetics - Cancer/Cancer FISH
View write-up

Indications

​FISH test using HER2 (ERBB2) DNA-probe is used in the detection of amplification of the HER2 (ERBB2) gene that plays a key role in the regulation of cell growth. This gene is amplified in some patients with human breast and gastric cancer. These patients respond well to trastuzumab (Herceptin®) treatment.

Specimen Required

​Newly-cut fresh breast cancer sections is ideal.

Storage and Transport

​The FISH test is optimal with fresh tissue samples. Tissue sections should preferably be between 4 - 6mm in thickness on coated/positively-charged slides. The optimal fixation time in formalin should be between 6 - 72 hours. An accompanying Hematoxylin and Eosin (H&E) stained slide with the invasive tumour region marked out by a pathologist should be submitted together with at least 3 unstained sections.

Method

​Fluorescence In Situ Hybridization using direct-labelled LSI HER2 (ERBB2) and CEP 17 DNA probes are hybridized to target loci and analysed under fluorescence microscopy.

Test Results

​Findings are reported in accordance to the International System for Human Cytogenomic Nomenclature (ISCN, 2020).

Reference Interval / Value

​ASCO/CAP guidelines - Reference ranges for ERBB2 amplification:
1. Positive - Ratio greater or equal to 2.0.
2. Positive - Ratio less than 2.0 with average ERBB2 copy numbers greater or equal to 6.0 signals/cell.
3. Equivocal - Ratio less than 2.0 with average ERBB2 copy numbers greater or equal to 4.0 and less than 6.0 signals/cell.
4. Negative - Ratio less than 2.0 with average ERBB2 copy numbers less than 4.0 signals/cell.

For gastric/GEJ carcinomas, results are positive if the ratio is ≥2.0

Turnaround Time

​3 ~ 9 days

Day(s) Test Set up

​Monday – Saturday (office hours)

Change History Notes

  • 02 Feb 2015 4:30 AM

    Revised Turnaround Time to within 9 days.

  • 07 Dec 2015 8:40 AM

    Updated Turnaround Time: 3 ~ 10 days

  • 06 Jul 2017 3:10 AM

    Updated the test result for ISCN, 2013 to ISCN, 2016

  • 17 May 2022 3:15 AM

    ​Updated the test result for ISCN, 2016 to ISCN, 2020

    Updated Turnaround Time: 3 ~ 9 days

TOP
Last updated on 17 May 2022