Comparison of HER2/neuStatus Assessed by Quantitative Polymerase Chain Reaction and Immunohistochemistry

Frances P. O'Malley, Robert Parkes, Eleanor Latta, Suzanna Tjan, Tanya Zadro, Rosemary Mueller, Nona Arneson, Martin Blackstein, Irene Andrulis
2001 American Journal of Clinical Pathology  
A b s t r a c t We prospectively evaluated a series of 254 breast cancers by quantitative polymerase chain reaction (PCR) and immunohistochemistry using 3 antibodies: HercepTest, CB11, and TAB250. DNA was extracted from a 10-µm tumor section for PCR, and 4-µm serial sections were taken from the same block for immunohistochemistry. The immunohistochemical results were scored using a semiquantitative immunohistochemical system. A positive tumor by immunohistochemistry had a score of 5 or more.
more » ... re of 5 or more. The manufacturer's recommended scoring system was used for the HercepTest. Tumors were positive for gene amplification if the ratio of the HER2/neu gene to control gene after normalization was 2 or more. Of 254 cases, 61 showed gene amplification. For immunohistochemistry, 23% of tumors were positive with CB11, 27% with TAB250, and 37% with the HercepTest. Results for each antibody were compared with PCR results. The overall concordance for the HercepTest was 82%, which was significantly lower than that for CB11 (88%) or TAB250 (87%). The specificity for the HercepTest was 80% compared with 90% for TAB250 and 93% for CB11, while the positive predictive value for the HercepTest was 57% compared with 71% and 76% for TAB250 and CB11, respectively. Anatomic Pathology / ORIGINAL ARTICLE Am J Clin Pathol 2001;115:504-511 505
doi:10.1309/vp4w-5c55-7m09-6tx3 pmid:11293897 fatcat:3cf3d4tdpjbltlnvs7jzixsyay