Objective: To evaluate the reliability of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) expression in breast cancer by immunohistochemistry and discuss their influencing factors.
Methods: The pretreatment biopsy specimens were collected from 148 patients (from Beijing Cancer Hospital between 2004 to 2010) with invasive breast cancer. After reslicing and staining (ER:SP1, PR: 1E2, HER-2: 4B5), the status of ER, PR and HER-2 was analyzed by a pathological expert with automated imaging system Ariol MB-8. And their results were compared with the original reports.
Results: The concordance rates between original reports and automated image system were ER:76.35%, PR:49.32%, HER-2:63.51% while Kappa values 0.12 (P = 0.020) , 0.18 (P = 0.002) and 0.08 (P = 0.200) respectively. And the concordance rates between expert reports and automated image system were ER:93.92%, PR:81.08% and HER-2:76.35% while Kappa values 0.77 (P < 0.001) , 0.67 (P < 0.001) and 0.32 (P < 0.001) respectively.
Conclusion: For the expressions of ER, PR and HER-2, the disaccording results of original reports and automated image system may be mainly due to the differences of antibodies, staining methods and interpretations.