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HER-2/neu IHC, Breast Paraffin

Test Number 480376
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CPT

88360
Synonyms
  • c-erb-2
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  • Updated on 04/14/2025

Test Details

Methodology

Immunohistochemistry (IHC)

Result Turnaround Time

2 - 4 days

5 - 9 days

2 - 4 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Use

Equivocal results by IHC should be reflexed to HER2 FISH to determine overall status. HER-2/neu overexpression is a predictor of response to certain breast cancer therapies, including targeted immunotherapies.1-3 A positive IHC result (3+) or an equivocal result with ISH amplification provides eligibility for trastuzumab (HERCEPTIN®) and trastuzumab emtansine (KADCYLA®) therapies. This test can also be used to qualify patients as HER2-low (1+ IHC or 2+/ISH-) or HER2-ultralow (any staining of the membrane in greater than 0 and less than or equal to 10% of invasive tumor cells) for fam-trastuzumab-deruxtecan-nxki (ENHERTU®) eligibility determination.

The HER-2/neu protein is a product of the HER-2/neu oncogene, and the detection of overexpression of the HER-2/neu protein has been associated in clinical evaluations with a decreased survival time and a decreased time to relapse in patients with breast cancer.1-3 HER-2/neu overexpression is also a predictor of response to certain breast cancer therapies, including targeted immunotherapies.4-6

Equivocal results by IHC should be reflexed to HER2 FISH to determine overall status. HER-2/neu overexpression is a predictor of response to certain breast cancer therapies, including targeted immunotherapies.1-3 A positive IHC result (3+) or an equivocal result with ISH amplification provides eligibility for trastuzumab (HERCEPTIN®) and trastuzumab emtansine (KADCYLA®) therapies. This test can also be used to qualify patients as HER2-low (1+ IHC or 2+/ISH-) or HER2-ultralow (any staining of the membrane in greater than 0 and less than or equal to 10% of invasive tumor cells) for fam-trastuzumab-deruxtecan-nxki (ENHERTU®) eligibility determination.

Special Instructions

Fixation time and fixative used must be indicated on the test request form. Please direct any questions regarding this test to oncology customer service at 800-345-4363.

Limitations

Use of fixatives other than 10% neutral-buffered formalin or fixation times less than six hours or more than 72 hours may not yield reliable results. Decalcification procedures may negatively affect antigenicity and DNA quality.

Use of fixatives other than 10% neutral-buffered formalin or fixation times less than six hours or more than 48 hours may not yield reliable results.

Use of fixatives other than 10% neutral-buffered formalin or fixation times less than six hours or more than 72 hours may not yield reliable results. Decalcification procedures may negatively affect antigenicity and DNA quality.

Specimen Requirements

Specimen

Formalin-fixed, paraffin-embedded (FFPE) tumor

Volume

One paraffin block or five unstained, positively-charged tissue slides cut at 4 to 5 microns and dried for one hour at 60°C

Container

Paraffin block transport pouch or slide mailer

Collection Instructions

Specimen should be fixed in 10% neutral-buffered formalin. Time from tissue acquisition to fixation should be as short as possible. Fixation time should be between six and 72 hours according to ASCO/CAP guidelines.

Specimen should be fixed in 10% neutral-buffered formalin. Fixation time should be between six and 72 hours according to ASCO/CAP guidelines; however, the package insert indicates optimum fixation time between 18 and 24 hours.

Specimen should be fixed in 10% neutral-buffered formalin. Time from tissue acquisition to fixation should be as short as possible. Fixation time should be between six and 72 hours according to ASCO/CAP guidelines.

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Tumor other than breast tumor

References

Modi S, Jacot W, Yamashita T, Petukhova MN, Agafonov SV, Itkin GP. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. N Engl J Med. 2022 Jul 7;387(1):9-20. PubMed 35665782

PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody [package insert]. Roche Diagnostics; Jan 29, 2025.

Wolff AC, Hammond MEH, Allison KH, 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 Jul 10;36(20):2105-2122. PubMed 29846122
Modi S, Jacot W, Yamashita T, et al. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. N Engl J Med. 2022 Jul 7;387(1):9-20.3566578
PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody [package insert]. Roche Diagnostics; Sep. 29, 2022.
Wolff AC, Hammond MEH, Allison KH, 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 Jul 10;36(20):2105-2122.29846122

Modi S, Jacot W, Yamashita T, Petukhova MN, Agafonov SV, Itkin GP. Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer. N Engl J Med. 2022 Jul 7;387(1):9-20. PubMed 35665782

PATHWAY anti-HER-2/neu (4B5) Rabbit Monoclonal Primary Antibody [package insert]. Roche Diagnostics; Jan 29, 2025.

Wolff AC, Hammond MEH, Allison KH, 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 Jul 10;36(20):2105-2122. PubMed 29846122

Footnotes

1. Muss HB, Thor AD, Berry DA, et al. c-erbB-2 expression and response to adjuvant therapy in women with node-positive early breast cancer. N Engl J Med. 1994 May 5; 330(18):1260-1266. PubMed 7908410
 
2. Khoo US, Leong ASY. Biologic markers in breast cancer: An update. J Histotechnology. 1998; 21(4):317-325.
 
3. Fitzgibbons PL, Page DL, Weaver D, et al. Prognostic factors in breast cancer. College of American Pathologists Consensus Statement 1999. Arch Pathol Lab Med. 2000 Jul; 124(7):966-978. PubMed 10888772
1. Press MF, Pike MC, Chazin VR, et al. HER-2/neu expression in node-negative breast cancer: Direct tissue quantitation by computerized image analysis and association of overexpression with increased risk of recurrent disease. Cancer Res. 1993 Oct 15; 53(20):4960-4970. 8104689
2. Paik S, Hazan R, Fisher ER, et al. Pathologic findings from the National Surgical Adjuvant Breast and Bowel Project: Prognostic significance of erbB-2 protein overexpression in primary breast cancer. J Clin Oncol. 1990 Jan; 8(1):103-112. 1967301
3. Tandon AK, Clark GM, Chamness GC, Ullrich A, McGuire WL. HER-2/neu oncogene protein and prognosis in breast cancer. J Clin Oncol. 1989 Aug; 7(8):1120-1128. 2569032
4. Muss HB, Thor AD, Berry DA, et al. c-erbB-2 expression and response to adjuvant therapy in women with node-positive early breast cancer. N Engl J Med. 1994 May 5; 330(18):1260-1266. 7908410
5. Khoo US, Leong ASY. Biologic markers in breast cancer: An update. J Histotechnology. 1998; 21(4):317-325.
6. Fitzgibbons PL, Page DL, Weaver D, et al. Prognostic factors in breast cancer. College of American Pathologists Consensus Statement 1999. Arch Pathol Lab Med. 2000 Jul; 124(7):966-978. 10888772
1. Muss HB, Thor AD, Berry DA, et al. c-erbB-2 expression and response to adjuvant therapy in women with node-positive early breast cancer. N Engl J Med. 1994 May 5; 330(18):1260-1266. PubMed 7908410
 
2. Khoo US, Leong ASY. Biologic markers in breast cancer: An update. J Histotechnology. 1998; 21(4):317-325.
 
3. Fitzgibbons PL, Page DL, Weaver D, et al. Prognostic factors in breast cancer. College of American Pathologists Consensus Statement 1999. Arch Pathol Lab Med. 2000 Jul; 124(7):966-978. PubMed 10888772

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
480376 HER-2/neu Oncoprot, Paraffin 480449 HER-2/neu (C-erbB-2) 18474-7
480376 HER-2/neu Oncoprot, Paraffin 480458 Scoring Guide 19147-8
480376 HER-2/neu Oncoprot, Paraffin 480381 Comment 77202-0
480376 HER-2/neu Oncoprot, Paraffin 483256 Fixation Time N/A
480376 HER-2/neu Oncoprot, Paraffin 483257 Fixative N/A
480376 HER-2/neu Oncoprot, Paraffin 480233 Director Review 69426-5
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code480449
Result Code NameHER-2/neu (C-erbB-2)
UofM
Result LOINC18474-7
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code480458
Result Code NameScoring Guide
UofM
Result LOINC19147-8
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code480381
Result Code NameComment
UofM
Result LOINC77202-0
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code483256
Result Code NameFixation Time
UofM
Result LOINCN/A
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code483257
Result Code NameFixative
UofM
Result LOINCN/A
Order Code480376
Order Code NameHER-2/neu Oncoprot, Paraffin
Order Loinc
Result Code480233
Result Code NameDirector Review
UofM
Result LOINC69426-5