Estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 status in invasive breast cancer: a 3,198 cases study at National Cancer Center, China.

Smears from paraffin sections from 3,198 cases of surgical resection mammary carcinomas were assessed immunohistochemically for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expressions in National Cancer Center (NCC), China, to explore the correlation of these markers to each other, to tumor histologic subtype, and to explore breast cancer four molecular subtypes clinicopathological characteristics. Pathology material of surgical resection patients presenting to NCC during July 1, 2010-July 1, 2012 were reviewed for patients' age, tumor size, subtype, grade, and ER, PR, HER2 immunohistochemistry (IHC) status. For HER2 IHC 2+ score cases, fluorescence in situ hybridization was used, as the 2007 American society of clinical oncology/college of American pathologists guidelines. There were 3,198 cases, with a median age of 51 years, a mean tumor size of 2.1 cm, and 42.3 % lymph node positivity. Of all cases, 2,506 (78.4 %) were ER+, 2,548 (79.7 %) were PR+, and 816 (25.5 %) were HER2+. Among the four molecular subtypes of breast cancer, luminal A were the majority accounting for 65.3 %, and triple-negative breast cancer accounted for 9.2 %. ER, PR, and HER2 status showed a direct correlation to tumor onset age, tumor type, and grade of ductal carcinoma. Meanwhile the four subtypes of breast cancer differed from onset age, tumor size, lymph node metastasis, and tumor grade. This study was an important documentation of Chinese breast cancer patients and the report would serve as a baseline for other future studies.