An initial concordance analysis was performed comparing IHC
results from the Nigerian laboratory, which used whole sections, with
corresponding IHC results from the Chicago laboratory derived from
TMAs. The IHC test results for ER and PR from Nigeria were initially
scored into 5 categories based on percentage and intensity of IHC
reaction (Dako ER/PR pharmDx Interpretation Manual)[15], whereas
in Chicago, the results were scored using the 4-point scale of Reiner et
al[12]. For the purpose of comparison, we used the conversion table
proposed by Shousha[16]. Assessment of HER2 status was performed
according to recommendations of the American Society of Clinical
Oncology and College of American Pathologists[17].Forthis
concordance analysis, we had 155 comparable ER results, 164
comparable PR results, and 154 comparable HER2 results. Theκfor
ER results was 0.42, which indicates a moderate agreement. The PR
results had a similar concordance with a κof 0.41. The HER2 test
results had aκof 0.38, which demonstrates a fair agreement.