Trial Outcomes & Findings for Study of Human Epidermal Growth Receptor (HER2) Status Evaluation in Breast Cancer Pathology Samples (NCT NCT02580799)

A total of 5 trial sites (named as Sites A to E) along with 1 reference site (named as Abroad) participated in this study.

Study of Human Epidermal Growth Receptor (HER2) Status Evaluation in Breast Cancer Pathology Samples

IHC is a staining process performed on fresh/frozen breast cancer tissue. IHC is used to show whether or not the cancer cells have Human Epidermal Growth Receptor (HER2) and/or hormone receptors on their surface. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.

Inter-laboratory variation between the sites was assessed using Kappa test, K values were interpreted as follows: a) less than (\<) 0: less than chance agreement, b) 0.01-0.20: slight agreement, c) 0.21-0.40: fair agreement, d) 0.41-0.60: moderate agreement, e) 0.61-0.80: substantial agreement, and f) 0.81-0.99: almost perfect agreement.

IHC is a staining process performed on fresh/frozen breast cancer tissue. IHC is used to show whether or not the cancer cells have HER2 and/or hormone receptors on their surface. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.

Inter-laboratory variation between the sites was assessed using Kappa test, K values to be interpreted as follows: a) \<0: less than chance agreement, b) 0.01-0.20: slight agreement, c) 0.21-0.40: fair agreement, d) 0.41-0.60: moderate agreement, e) 0.61-0.80: substantial agreement, and f) 0.81-0.99: almost perfect agreement.

IHC is a staining process performed on fresh/frozen breast cancer tissue. IHC is used to show whether or not the cancer cells have HER2 and/or hormone receptors on their surface. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.

Inter-laboratory variation between the sites was assessed using Kappa test, K values to be interpreted as follows: a) \<0: less than chance agreement, b) 0.01-0.20: slight agreement, c) 0.21-0.40: fair agreement, d) 0.41-0.60: moderate agreement, e) 0.61-0.80: substantial agreement, and f) 0.81-0.99: almost perfect agreement.

IHC is a staining process performed on fresh/frozen breast cancer tissue. IHC is used to show whether or not the cancer cells have HER2 and/or hormone receptors on their surface. The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.

Inter-laboratory variation between the sites was assessed using Kappa test, K values to be interpreted as follows: a) \<0: less than chance agreement, b) 0.01-0.20: slight agreement, c) 0.21-0.40: fair agreement, d) 0.41-0.60: moderate agreement, e) 0.61-0.80: substantial agreement, and f) 0.81-0.99: almost perfect agreement.

Primary tumor diagnosis was classified into invasive ductal carcinoma, invasive ductal carcinoma + integrin linked kinase (ILK) antibody and mixed (invasive ductal + lobular) and reported.

TNM system is based on size of primary tumor (T), amount of spread to lymph nodes (N) and presence of metastasis (M). T1: tumor ≤20 millimeters (mm), T2: tumor \>20 mm to ≤50 mm, T3: \>50 mm and TX: tumor cannot be assessed. N0: no lymph node metastasis, N1: metastasis to ipsilateral level I, II axillary lymph nodes, N2: N1 metastasis that is clinically fixed/matted or in clinically detected ipsilateral internal mammary nodes, N3: metastases in ipsilateral infraclavicular lymph nodes, with/without level I, II axillary node involvement, or in clinically detected ipsilateral internal mammary lymph nodes and clinically evident level I, II axillary lymph node metastasis; or metastasis in ipsilateral supraclavicular lymph nodes, NX: Regional lymph nodes cannot be assessed. M0: no clinical/radiographic evidence of distant metastasis, M1: distant detectable metastases as determined by clinical and radiographic means and/or histologically proven \>0.2 mm, and MX: metastases cannot be assessed.

Modified Bloom-Richardson Grade scoring system was used which considers the amount of glandular/tubular differentiation, nuclear features and the mitotic activity of tumor cells. Tubular score (TS) 1: \>75 percent (%) of tumor area forming tubular structures, TS 2: 10% to 75% of tumor area forming tubular structures, TS 3: \<10% of tumor area forming tubular structures. Nuclear score (NS) 1: nuclei small with little increase in size in comparison with normal breast epithelial cells, regular outlines, uniform nuclear chromatin, little variation in size, NS 2: cells larger than normal with open vesicular nuclei, visible nucleoli, and moderate variability in both size and shape, NS 3: Vesicular nuclei, often with prominent nucleoli, exhibiting marked variation in size and shape, occasionally with very large and bizarre forms. Mitosis score (MS) 1: ≤7 mitoses per 10 high power fields, MS 2: 8-14 mitoses per 10 high power fields and MS 3: ≥15 mitoses per 10 high power fields.

Modified Bloom-Richardson Grade scoring system was used which considers the amount of glandular/tubular differentiation, nuclear features and the mitotic activity of tumor cells. Tubular, Nuclear and Mitosis scoring pattern was discussed in outcome 11, each score was added to give a final total score ranging from 3-9. Tumors with 3, 4 or 5 points are classified as being of low malignancy or Grade I, those with 6 or 7 points of intermediate malignancy or Grade II, and those with 8 or 9 points of high malignancy or Grade III.

Presence of hormone receptors was examined by the amount of uptake of estrogen and progesterone hormones when analyzed using IHC staining procedure.

The specific density of hormone receptors was examined by the amount of uptake of estrogen and progesterone hormones when analyzed using IHC staining procedure. Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.

Reference site was considered as Abroad and the tests were performed in a laboratory in Amsterdam, Netherlands. A total of 150 data registration forms (120 forms from trial sites \[24 from each site\] and 30 from the reference site) were collected.

Different slide stainers like Ventana, Ventana Benchmark 4XT, Ventana Benchmark Ultra and Ventana Benchmark XT were used to report HER2 test results on data registration forms (120 forms from trial sites \[24 from each site\] and 30 from the reference site).

Fixation of tissue samples cross-link proteins and masks antigenic sites; antigen retrieval process was performed before IHC staining in order to reverse the masking of antigenic sites. Antigen retrieval process was performed in this study using the following solutions: 1 hour Cell Conditioning 1 (CC1), 30 minutes (min) CC1 mild, 64 min CC1, CC1 Ethylenediaminetetraacetic acid (EDTA) standard, and Cell Conditioning 2 (CC2) 30 min.

The primary antibodies included; Biocabe EP 10454, Cerb B2 (SP3 clone), Her2 Neu (SP3) Cell marque, Neomarkers (thermo) cerb B2-Ab-17 and Thermo SP3.

The IHC test gives a score of 0 to 3+ that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. If the score is 0 to 1+, it's called "HER2 negative." If the score is 2+, it's called "borderline." A score of 3+ is called "HER2 positive." Score 0: cells free from immune staining, score 1 (+): is concluded in the case of stains not completely membranous and which do not surround the membranes regardless of quantity in the cells, or weak stains surrounding the entire membrane in less than 10% of the cells. Score 2 (++): is concluded in the presence of a moderate staining surrounding the cytoplasmic membrane in at least 10%, or strong membranous staining in less than 30% of the invasive carcinoma cells. Score 3 (+++): is concluded where IHC yields strong staining surrounding the entire cytoplasmic membrane in at least 30% of the invasive carcinoma cells.