Aim: Although immunohistochemistry (IHC) and reverse transcription-PCR can detect ALK rearrangements, the ALK break-apart FISH assay is currently considered the standard method.
Materials & methods: Five patients with advanced non-small-cell lung cancer, who had an ALK-negative FISH result that was later confirmed as positive by the Ventana IHC assay, were studied. Four had previously received chemotherapy or radiotherapy. All five were subsequently treated with Crizoitinib 250 mg twice daily.
Results & conclusion: Four patients had a partial response to Crizotinib and one had stable disease. IHC is an efficient technique for diagnosing ALK rearrangements in patients with non-small-cell lung cancer, and may serve as an alternative to FISH in clinical practice.
Keywords: ALK; Crizotinib; FISH; diagnosis; immunohistochemistry; non-small-cell lung cancer.