title: HER2 status determination: analyzing the problems to find the solutions.
abstract: Misdiagnosis in the evaluation of HER2 status in breast cancer may have consequent negative impact on clinical decision-making. Therefore, it has become ever more important to share procedures and interpretation criteria for HER2 testing among laboratories. Herein, we report an interlaboratory survey among 9 hospitals located in the central-south regions of Italy. The centers sent a series of 36 slides, 4 for each HER2 score, to the revising centers. We found a good concordance in HER2 scoring for 0 and 3+ score, but a very low concordance for 1+ and 2+ scores. To focus on factors that may lead to discordant results, we report 4 cases which summarized the most common source of discrepancy in HER2 testing. This methodological approach will help the individual laboratory to minimize technical variables and to reduce the percentage of erroneous interpretations of HER2 status.
authors.affiliation: From the Biostatistics, Scientific Direction, Regina Elena National Cancer Institute (IT); Pathology Department Catholic University of Sacred Heart (IP, VA); and Pathology Department Regina Elena National Cancer Institute-Rome, Italy (SB, MM).
authors.forename: Irene
authors.initials: I
authors.lastname: Terrenato
authors.forename: Ilaria
authors.initials: I
authors.lastname: Pennacchia
authors.forename: Simonetta
authors.initials: S
authors.lastname: Buglioni
authors.forename: Marcella
authors.initials: M
authors.lastname: Mottolese
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Arena
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D005821:Genetic Techniques; D006801:Humans; D007150:Immunohistochemistry; D015588:Observer Variation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D015203:Reproducibility of Results
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human