Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Update

Abstract

The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to > 10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing. This guideline was developed through a collaboration between the American Society of Clinical Oncology and the College of American Pathologists and has been published jointly by invitation and consent in both Journal of Clinical Oncology and the Archives of Pathology & Laboratory Medicine.

Fascin‐1 as a novel diagnostic marker of triple‐negative breast cancer

“…A case was considered to be ER or PR positive if the percentage of positive invasive cancer cells (nuclear staining) was >5%12. HER2 status was assessed according to the 2013 American Society of Clinical Oncology/College of American Pathologists guidelines for HER2 testing in breast cancer 17.…”

HER 2 immunohistochemistry for breast cancer cell blocks can be used in the same way as that used for histological specimens

“…Evaluation of the HER2 receptor status at metastatic sites is important for selecting the correct chemotherapy for treatment of recurrent disease 1. Cytology can be applied to several types of metastatic lesion from which biopsies may be difficult to obtain, a particular example being from body cavity fluids.…”

“…The staining and assay were performed with a Ventana BenchMark ULTRA (Roche Diagnostics, Basel, Switzerland). The 2013 ASCO/CAP criteria for HER2 testing in breast cancer1 was used to categorize the results. Fifty‐two out of 54 cases were analyzed.…”

“…Human epidermal growth factor receptor 2 (HER2) testing of samples from recurrent or metastatic breast cancers is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines1 because of potential differences in HER2 status between primary and metastatic breast cancer sites. Cytological analysis can be applied to several types of metastatic lesion as well as to body cavity fluids, and it is a useful approach for patients in poor clinical condition.…”

Application of a novel prognostic invasive lesion index in ductal carcinoma in situ with minimal invasion of the breast

“…The molecular subtypes were as follows: Luminal A (ER positive, PR positive, HER‐2 negative and Ki67 ≤ 14%), Luminal B (ER positive and HER‐2 positive or Ki67 > 14%), HER‐2 overexpressing (ER negative, PR negative, and HER‐2 positive), and triple‐negative breast cancer (ER negative, PR negative, and HER‐2 positive). HER‐2 positive was defined as immunohistochemical grade of 3+ or determined by fluorescence in situ hybridization as positive 11. In addition, other clinical data were also obtained from the database, including age at diagnosis, menstrual status, lymph node status, local or regional recurrence, distant metastasis and death events, the date of recurrence, metastasis, death, and last follow‐up.…”