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Test Code MISC2MAYOHERMB HER2, Breast, Semi-Quantitative Immunohistochemistry, Manual with HER2 FISH Reflex


Ordering Guidance


For gastroesophageal cancer, order HERGM / HER2, Gastric/Esophageal, Semi-Quantitative Immunohistochemistry, Manual or HERGN / HER2, Gastric/Esophageal, Semi-Quantitative Immunohistochemistry, Manual, No Reflex.



Shipping Instructions


Attach the green "Attention Pathology" address label (T498) to the outside of the transport container before putting into the courier mailer.



Necessary Information


1. An accompanying pathology report stating the final diagnosis is required. If not available, a preliminary diagnosis is acceptable only if it refers to invasive or metastatic breast carcinoma.

2. Information regarding fixative used, time to fixation, and duration of fixation as well as tumor type and classification is required.

The following questions, as stated on the Pathology/Cytology Information (T707) form or presented electronically, must be answered:

 a. "Was specimen fixed in 10% neutral buffered formalin within 1 hour from surgical collection time? Yes, No, or Unknown."

 b. "Has specimen been fixed in 10% neutral buffered formalin for 6 to 72 hours? Yes, No, or Unknown."

 c. "Was tissue decalcified? Yes, No or Unknown."

 d. "Tumor type? Primary invasive breast carcinoma or metastatic breast carcinoma."

 e. "Tumor classification? Invasive breast carcinoma, metastatic breast carcinoma, or micro-invasive breast carcinoma."



Specimen Required


Supplies: Pathology Packaging Kit (T554)

Specimen Type:

Preferred: A paraffin-embedded tissue block containing breast cancer tissue that has been fixed in 10% neutral buffered formalin within 1 hour from surgical collection time and for a total of 6 to 72 hours.

Acceptable: 5 Unstained sections containing breast carcinoma on charged slides cut at 4 microns less than 1 month ago. Tissue on the slides should have been fixed in 10% neutral buffered formalin within 1 hour from surgical collection time and for a total of 6 to 72 hours.

Container/Tube: Pathology Packaging Kit

Collection Instructions: Submit paraffin-embedded invasive or metastatic breast carcinoma tissue.

Additional Information:

1. According to the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines, HER2 protein immunohistochemical test results are only valid for nondecalcified, paraffin-embedded specimens fixed in 10% neutral buffered formalin within 1 hour from surgical collection time and for a total time of 6 to 72 hours. Delay to fixation, or under- or over-fixation may affect these results.(1)

2. HER2 immunohistochemistry testing on intracystic papillary carcinoma and solid papillary carcinoma, without clearly stating invasive carcinoma, is not appropriate and will be reported as indeterminate.

3. Paraffin blocks will be returned with final report.


Forms

If not ordering electronically, complete, print, and send with the specimen:

1. Pathology/Cytology Information (T707) is required if not ordering electronically.

2. Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763)

Secondary ID

620800

Useful For

Determining overexpression of HER2 protein on formalin-fixed, paraffin-embedded tissue sections

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
H2BR HER2, Breast Tumor, FISH, Tissue Yes No

Testing Algorithm

Cases that are equivocal (2+) by immunohistochemical stain will reflex to HER2 amplification by fluorescence in situ hybridization at an additional charge.

Special Instructions

Method Name

Immunoperoxidase Stain with Manual Quantitative Immunohistochemistry (IHC)

Reporting Name

HER Breast SemiQuant IHC + Reflex

Specimen Type

Special

Specimen Stability Information

Specimen Type Temperature Time Special Container
Special Ambient (preferred)
  Refrigerated 

Reject Due To

No specimen should be rejected.

Clinical Information

The HER2 (official gene name ERBB2) proto-oncogene encodes a membrane receptor with tyrosine kinase activity and homology to the epidermal growth factor receptor. Amplification and overexpression of the HER2 gene in human breast, endometrial, ovarian, and other epithelial cancers have been associated with a shorter disease-free interval and shorter overall survival. Overexpression of HER2 protein is an indication for Herceptin (trastuzumab) therapy in patients with breast cancer.

 

This test is most frequently used to evaluate HER2 overexpression in breast cancer.

Reference Values

Reported as negative (0, 1+), equivocal (2+), and strongly positive (3+) according to the interpretation guidelines for the US Food and Drug Administration-approved Ventana Pathway HER2 (4B5) antibody.

Interpretation

Results are reported as negative (0, 1+), equivocal (2+), and strongly positive (3+) according to the published American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) interpretation guidelines.(1)

Method Description

Testing is performed using US Food and Drug Administration-approved Ventana Pathway HER2 (4B5) rabbit monoclonal primary antibody and a proprietary detection system, using modified manufacturer’s instructions.(Package insert: PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody. Ventana Medical Systems, Inc; 09/2022)

 

Scoring is performed according to American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines as follows:

Score of 3+ is defined as circumferential membrane staining that is complete, intense and in greater than 10% of invasive tumor cells.

Score of 2+ is defined as weak to moderate complete membrane staining observed and in greater than 10% of the invasive tumor cells; or circumferential membrane staining that is complete, intense and in less than or equal to 10% of invasive tumor cells.

Score of 1+ is defined as incomplete membrane staining that is faint or barely perceptible and in greater than 10% of the invasive tumor cells; or weak to moderate complete membrane staining observed and less than 10% of the invasive tumor cells.

Score of 0 is defined as no staining observed or membrane staining that is incomplete and is faint or barely perceptible and in less than or equal to 10% of the invasive tumor cells.(Wolff AC, Hammond ME, Hicks DG, et al. Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Focused Update. J Clin Oncol. 2018;36(20):2105-2122 doi:10.1200/JCO.2018.77.8738)

Day(s) Performed

Monday through Friday

Report Available

5 to 15 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88360

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HERMB HER Breast SemiQuant IHC + Reflex 85319-2

 

Result ID Test Result Name Result LOINC Value
620801 Interpretation 50595-8
620802 Participated in the Interpretation No LOINC Needed
620803 Report electronically signed by 19139-5
620804 Material Received 81178-6
MA058 Fixed in 10% NB formalin w/in 1 hr 8100-0
MA059 Fixed in 10% NB formalin 6-72 hrs 8100-0
MA060 Tumor type 44638-5
MA061 Tumor classification 21918-8
MA062 Tissue was decalcified 8100-0
620805 Disclaimer 62364-5
620806 Case Number 80398-1