RT Journal Article
SR Electronic
T1 The effect of delay in fixation on HER2 expression in invasive carcinoma of the breast assessed with immunohistochemistry and in situ hybridisation
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 573
OP 575
DO 10.1136/jclinpath-2013-201978
VO 67
IS 7
A1 Andrew H S Lee
A1 Heather P Key
A1 Jane A Bell
A1 Patrick Kumah
A1 Zsolt Hodi
A1 Ian O Ellis
YR 2014
UL http://jcp.bmj.com/content/67/7/573.abstract
AB Aims Accurate assessment of HER2 status is essential for selection of patients for HER2-targeted treatment such as trastuzumab. This study investigated the hypothesis that delayed fixation impairs HER2 assessment. Methods 9 carcinomas were received fresh, and samples were fixed immediately or put in fixative at time intervals up to 24 h. All carcinomas were scored as 3+ with immunohistochemistry in properly fixed tissue. Results 2 of 9 carcinomas (95% CIs 6% to 56%) showed reduced immunohistochemical staining with delays in fixation of 1 and 8 h. One carcinoma showed low-level amplification with fluorescence in situ hybridisation (FISH) when properly fixed and was not amplified after delayed fixation. The other carcinomas were amplified at all time points. Conclusions Delayed fixation impaired HER2 protein expression assessed using immunohistochemistry in 22% of 3+ carcinomas. HER2 amplification assessed using FISH may be less affected.