Er clone sp1

The expression of the basic biomarkers including ER, PR, HER2, p53, and Ki-67 was evaluated from the surgical specimens at the time of diagnosis. As for those with missing data, immunohistochemical staining on representative tissue sections was carried out using the following antibodies: ER (clone SP1; 1:100 dilution; LabVision, Fremont, CA), PR (clone PgR 636; 1:70 dilution; Dako, Carpinteria, CA), HER2 (clone 4B5; ready to use; Ventana Medical Systems, Tuscon, AZ), p53 (clone D07; 1:600 dilution; Dako), and Ki-67 (clone MIB-1; 1:250 dilution; Dako).
ER and PR were regarded as positive if at least 1% of the tumor cells were stained. HER2 positivity was defined as an immunohistochemical score of 3+ or the presence of gene amplification on fluorescence/silver in situ hybridization. For p53, staining in 10% or more of the tumor cells was considered positive. High Ki-67 proliferation index was defined as staining in 10% or more of the tumor cells.

Expression of the basic biomarkers including ER, PR, HER2, p53, and Ki-67 was evaluated at the time of pathologic diagnosis in the surgical specimens. The antibodies stained were as follows; ER (clone SP1; 1:100 dilution; LabVision, Fremont, CA), PR (clone PgR 636; 1:70 dilution; Dako, Carpinteria, CA), HER2 (clone 4B5; ready to use; Ventana Medical Systems, Tuscon, AZ), p53 (clone D07; 1:600 dilution; Dako), and Ki-67 (clone MIB-1; 1:250 dilution; Dako). ER and PR staining in ≥ 1% of the tumor cells was determined as positive. Patients with ER- or PR-positive tumors were regarded as hormonal receptor (HR)-positive. HER2 positivity was defined as an immunohistochemical score of 3+ or the presence of HER2 gene amplification on fluorescence/silver in situ hybridization. For p53, staining in 10% or more of the tumor cells was considered positive. High Ki-67 proliferation index was defined as staining in ≥ 10% of tumor cells for DCIS and ≥ 20% for IBC.
Breast cancer subtype was determined with standard biomarker profiles according to 2011 St Gallen International Expert Consensus^{37 (link)}. Each subtype was defined as follows: luminal A (ER+ and/or PR+, HER2−, Ki-67 < 14%), luminal B (ER+ and/or PR+, HER2−, Ki-67 ≥ 14%; ER+ and/or PR+, HER2+), HER2+ (ER−, PR−, HER2+), and triple-negative (ER−, PR−, HER2−).