MOESM1 of External quality assessment (EQA) program for the immunohistochemical detection of ER, PR and Ki-67 in breast cancer: results of an interlaboratory reproducibility ring study in China

Additional file 1: Table S1. Standardized IHC staining procedures of RCs. Figure S1. Observed agreement between 3 RCs and the reference value. Three RCs, the Department of Pathology, West China Hospital, Sichuan University, the Department of Pathology of Peking Union Medical College Hospital and the Shanghai Cancer Center of Fudan University, stained the slides by standardized procedures using three kinds of antibodies. As all RCs obtained the same results, the proportions of tumour nuclei positive for ER-1, ER-2 and ER-3 were 11–50%, > 50 and 0%, respectively. For the PR tests, the reference values were > 50% for PR-1, 1–10% for PR-2 and 0% for PR-3. For the Ki-67 tests, the reference values were > 30% for KI-1, KI-2 and KI-5; 10–30% for KI-3; and < 10% for KI-4. RCs: revising centres