Xiaohong Han1, Yuankai Shi1, Li Ma1, Zheng Lyu1, Hongying Yang2, Jiarui Yao1, Jian Li1, Bo Li1, Yan Qin1. 1. Department of Medical Oncology, Beijing Key Laboratory of Clinical Study on Anti-cancer Molecular Targeted Drugs, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China. 2. Department of Pathology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
Abstract
BACKGROUND: Accurate detection of human epidermal growth factor receptor 2 (HER2) expression and gene amplification is crucial for the application of HER2-specific therapy and for evaluating the response of patients with breast cancer. A uniform and standard procedure of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) needs to be established for evaluating the HER2 status in breast cancer tissues for the treatment of patients with real HER2-positive tumors. The present multicenter study was aimed to examine the HER2 status in breast cancer specimens from Chinese patients using both IHC and FISH methods. METHODS: A multicenter study was performed on the HER2 status in 3 149 breast cancer specimens from different ethnic populations and areas in China by IHC and FISH assays. The potential association of HER2 status with demographic and clinical characteristics was analyzed. RESULTS: The positive rates for HER2 over-expression and HER2 amplification were 23.3% and 27.5% in this study, respectively. The concordance between IHC and FISH was 71.2% (κ = 0.494, P < 0.001). Furthermore, 72.9% of specimens with IHC 2+ were negative to FISH. The discordance rates among laboratories were from 5% to 28% for IHC and 1% to 16% for FISH. HER2 amplification was associated significantly with advanced tumor stage (III or IV, P = 0.002), large tumor size (>5 cm, P = 0.002), moderate and poor histological grades (P < 0.0001), post-menopause (P < 0.0001), ER-PR- (P = 0.002), and having ≥ 4 lymph nodes affected (P < 0.0001) in this population. The positive rates of HER2 amplification in specimens from Man and Hui Chinese were significantly higher than that in other Chinese populations. There are slightly higher positive rates of HER2 expression and amplification in Chinese patients with breast cancer. CONCLUSION: These findings may provide new insights into understanding the epidemiological features of HER2 expression and amplification, and may be valuable for clinical practice.
BACKGROUND: Accurate detection of humanepidermal growth factor receptor 2 (HER2) expression and gene amplification is crucial for the application of HER2-specific therapy and for evaluating the response of patients with breast cancer. A uniform and standard procedure of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) needs to be established for evaluating the HER2 status in breast cancer tissues for the treatment of patients with real HER2-positive tumors. The present multicenter study was aimed to examine the HER2 status in breast cancer specimens from Chinese patients using both IHC and FISH methods. METHODS: A multicenter study was performed on the HER2 status in 3 149 breast cancer specimens from different ethnic populations and areas in China by IHC and FISH assays. The potential association of HER2 status with demographic and clinical characteristics was analyzed. RESULTS: The positive rates for HER2 over-expression and HER2 amplification were 23.3% and 27.5% in this study, respectively. The concordance between IHC and FISH was 71.2% (κ = 0.494, P < 0.001). Furthermore, 72.9% of specimens with IHC 2+ were negative to FISH. The discordance rates among laboratories were from 5% to 28% for IHC and 1% to 16% for FISH. HER2 amplification was associated significantly with advanced tumor stage (III or IV, P = 0.002), large tumor size (>5 cm, P = 0.002), moderate and poor histological grades (P < 0.0001), post-menopause (P < 0.0001), ER-PR- (P = 0.002), and having ≥ 4 lymph nodes affected (P < 0.0001) in this population. The positive rates of HER2 amplification in specimens from Man and Hui Chinese were significantly higher than that in other Chinese populations. There are slightly higher positive rates of HER2 expression and amplification in Chinese patients with breast cancer. CONCLUSION: These findings may provide new insights into understanding the epidemiological features of HER2 expression and amplification, and may be valuable for clinical practice.
Authors: Muhammad Afzal; Mohammed Amir; Muhammad Jawad Hassan; Muhammad Sikander Hussain; Muhammad Naveed Aziz; Sheeba Murad; Iram Murtaza; Mariam Anees; Aneesa Sultan Journal: Tumour Biol Date: 2016-01-06