The relation between percentage of immunostained cells and amplification status in breast cancers with equivocal result for Her2 immunohistochemistry

We analyzed Her2 amplification in breast cancers with equivocal IHC staining to investigate the significance of percentage of Her2 immunostained tumor cells. We especially included the breast cancers with complete/incomplete membrane staining at moderate intensity in less than 10% of the invasive tumor cells.