Test Catalog

Test ID: H2BR    
HER2 Amplification Associated with Breast Cancer, FISH, Tissue

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Reflex testing will be performed using immunohistochemistry (IHC) when the FISH result falls within certain ranges as defined by the 2018 focused update to the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.(1) For FISH results in ASCO/CAP categories Group 2, 3, and 4 (formerly called "equivocal"), the IHC testing will be added, charged, and reported separately. An integrated interpretation of the IHC and FISH results will be provided (see Interpretation).


A charge and CPT code is applied for each probe set hybridized, analyzed, and reported.

Specimen Type Describes the specimen type validated for testing


Ordering Guidance

This test is only for primary or metastatic breast tumors.

-For urothelial tumors, order H2UR / HER2 Amplification Associated with Urothelial Carcinoma, FISH, Tissue.

-For gastroesophageal tumors, order H2GE / HER2 Amplification Associated with Gastroesophageal Cancer, FISH, Tissue.

-For all other tumor types, order H2MT / HER2 Amplification, Miscellaneous Tumor, FISH, Tissue.


This test does not include a pathology consult. If a pathology consult is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be determined by the reviewing pathologist and testing performed at an additional charge.

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

1. A pathology report is required in order for testing to be performed. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.

2. A reason for testing must be provided. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.

3. The pathology report must include type and time of fixation, as well as the cold ischemia time.

Specimen Required Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Note: In accordance to CAP guidelines, place specimens for HER2 (ERBB2) testing in fixative within one hour of biopsy or resection (cold ischemia time). Specimens should remain in 10% neutral buffered formalin for a minimum of six hours to a maximum of 72 hours (formalin fixation time). Do not use decalcification solutions with strong acids.(2)


Submit only 1 of the following specimens:


Specimen Type: Tissue

Preferred: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block.


Acceptable: Slides

Collection Instructions: Four consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Two consecutive, unstained, 5-micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container
TissueAmbient (preferred)