Discordant Results between Immunohistochemistry (IHC) and Fluorescence in Situ Hybridization (FISH)

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Discordant Results between Immunohistochemistry (IHC) and Fluorescence in Situ Hybridization (FISH)

Discordant results between IHC and FISH are observed in approximately 4% of cases tested. Examples of result discordance are:
  • IHC is 3+ but FISH is negative for amplification
  • IHC < 2+ but FISH is positive for amplification
Available clinical data is insufficient in determining whether this discordance represents distinct biologic subgroups or if test results should be considered inaccurate.