these markers, therefore, would nat

these markers, therefore, would naturally depend on the accurate,
reliable, and reproducible determination of their presence and levels
in individual breast tumors.
Immunohistochemistry (IHC) has so far been used for ER, PR, and
HER2 determination. However, despite long-term use worldwide,
there still exists significant intralaboratory and interlaboratory
variability of IHC results. Some identified reasons for interlaboratory
discrepancies include the following: type of antibody clone used,
differences in antigen retrieval techniques, formalinfixation time, and
different scoring/reporting systems. As a result, an ad hoc consensus
conference, consisting of directors from a broad range of IHC
laboratories, was convened in 2006, which put together recommendations aimed at standardizing IHC laboratory practices[8,9]. The
factors considered at the conference included preanalytic factors,
which focus onfixation techniques; analytic factors, which talk about
antigen retrieval procedure; and postanalytic factors, which discuss
the scoring and reporting systems. Some of the specific recommendations made at this conference include the exclusive use of formalin
fixatives, the need for adequatefixation time, careful selection of
antibody clone, and the use of an efficient scoring system.
In Nigeria, IHC determination of breast tumor markers has just
recently been introduced. Only a handful of laboratories offer these
tests currently, and it is important to set up quality measures to
assure accurate performance of IHC analysis of breast tissues to guide
treatment decisions. The aim of this study therefore is to examine
the reproducibility of test results obtained from a field laboratory
in Nigeria in comparison with data obtained from a wellestablished laboratory at the University of Chicago, Illinois, using
tissue microarray (TMA) technology. We also assessed the
feasibility of Web-based conferences and digital microscopy in