Hopefully, ASCO and CAP will relax their fixation guidelines for HER2 testing in the near future to reflect that prolonged fixation in formalin has little, if any, affect on HER2 protein overexpression (my personal experience). Another article (see below) just appeared in the October issue of the American Journal of Clinical Pathology that supports this observation. Please keep in mind that making sure that the tissue doesn't dry out, minimizing the "cold" ischemic time to under 1 hour, and submitting "thin" (2-3 mm) sections for histological processing are probably more important than time in formalin.
Ibarra JA and Rogers LW: Fixation time does not affect expression of HER2/neu. Am J Clin Pathol 2010;134:594-596. 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 Office (860) 545-2204 Fax _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet