Objective: To investigate the standard protocol for anaplastic lymphoma kinase (ALK) fusion gene assessment by fluorescent in situ hybridization (FISH) in non-small cell lung cancer (NSCLC).
Methods: Tissue specimens of NSCLC cases were retrospectively collected from Jan. 2011 to July 2012. ALK fusion gene was examined by FISH using break-apart ALK gene probes (Vysis company). The identification of ALK fusion gene was determined by fluorescent signals under a fluorescence microscope.
Results: One hundred and forty-six eligible NSCLC tumor specimens were tested for ALK fusion gene by FISH. The specimens included 110 cases (75.4%) of surgically-removed tissues, 11 cases (7.5%) of biopsy, 19 cases (13.0%) of lymph node and 6 cases (4.1%) of other metastatic tissues. The positivity of ALK fusion gene was 8.9% (13/146).
Conclusions: The assessment of ALK fusing gene by FISH using standard protocol for formalin-fixed, paraffin-embedded (FFPE) tissue is feasible. The protocol can used to test in surgically-removed tissues, biopsies, metastatic lymph nodes and other metastastic specimens.