[Histonet] Breast processing

[Richard Cartun]

My personal experience is that formalin fixation for 72 hours (and longer) does not affect immunoreactivity for ER, PR, and HER2 protein overexpression as long as the tissue does not "dry-out" before being placed in formalin and "thin" (2-3 mm) sections are submitted for fixation and histologic processing.  There have been several articles published recently that support this observation including one from 2002 (5 years before the ASCO/CAP guidelines were published!).  In fact, I would like someone to show me where the scientific evidence is for supporting these "guidelines".  Remember, these are "guidelines"; you are permitted to experiment, validate, and write-up your own fixation policy for your institution.

Arber D:  Effect of prolonged formalin fixation on the immunohistochemical reactivity of breast markers.  Appl Immunohistochem Mol Morphol 2002;10:183-186.

Ibarra JA, Rogers LW:  Fixation time does not affect expression of HER2/neu.  Am J Clin Pathol 2012;134:594-596.

Tong LC, Nelson N, Tsourigiannis J, et al.:  The effect of prolonged fixation on the IHC evaluation of ER, PR, and HER2 expression in invasive breast cancer: a prospective study.  Am J Surg Pathol 2011;35:545-552.

I apologize to the authors of the other studies, but I had immediate access to these references since I gave a lecture on this topic today.

Richard



Richard W. Cartun, MS, PhD
Director, Histology & Immunopathology
Director, Biospecimen Collection Programs
Assistant Director, Anatomic Pathology
Hartford Hospital
80 Seymour Street
Hartford, CT  06102
(860) 545-1596
(860) 545-2204 Fax


>>> "Gudrun Lang" <gu.lang <@t> gmx.at> 10/8/2012 3:31 PM >>>
Is there any evidence, that NBF-fixation for 72 hours alters Her2 staining, so that there's  a diagnostic difference (pos./neg.)? publications with data?
Personal experience?
I have the feeling, that there is a mythos of overfixation. Anybody else ...?
I saw turning up and down of Her2 results due to non-standardized staining-protocols.  
But I think a protocol, that fits to a 48 hours-fixed tissue fits also to 72 hours.

Gudrun Lang


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