Screening of Anaplastic Lymphoma Kinase Rearrangement by Immunohistochemistry in Non-small Cell Lung Cancer: Correlation with Fluorescence In Situ Hybridization

• Published in: Journal of thoracic oncology Vol. 6; no. 3; pp. 466 - 472
• Main Authors: Paik, Jin Ho, Choe, Gheeyoung, Kim, Hyojin, Choe, Ji-Young, Lee, Hyun Ju, Lee, Choon-Taek, Lee, Jong Seok, Jheon, Sanghoon, Chung, Jin-Haeng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2011; International Association for the Study of Lung Cancer
• Subjects: Adenocarcinoma - diagnosis; Adenocarcinoma - genetics; Adenocarcinoma - metabolism; Adult; Aged; Aged, 80 and over; Carcinoma, Large Cell - diagnosis; Carcinoma, Large Cell - genetics; Carcinoma, Large Cell - metabolism; Carcinoma, Non-Small-Cell Lung - diagnosis; Carcinoma, Non-Small-Cell Lung - genetics; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Squamous Cell - diagnosis; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Cohort Studies; EML4-ALK; Female; Fluorescence in situ hybridization; Follow-Up Studies; Gene Rearrangement; Humans; Immunoenzyme Techniques; Immunohistochemistry; In Situ Hybridization, Fluorescence; Lung Neoplasms - diagnosis; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Male; Middle Aged; Neoplasm Staging; Non-small cell lung cancer; Prognosis; Receptor Protein-Tyrosine Kinases - genetics; Receptor Protein-Tyrosine Kinases - metabolism; Retrospective Studies; Sensitivity and Specificity; Tissue Array Analysis; Young Adult; EML4-ALK; Immunohistochemistry; Non-small cell lung cancer; Fluorescence in situ hybridization
• ISSN: 1556-0864; 1556-1380; 1556-1380
• DOI: 10.1097/JTO.0b013e31820b82e8

The use of a standard immunohistochemistry (IHC) assay to detect the anaplastic lymphoma kinase (ALK) protein in lung cancer is challenging. There are no universally accepted, evidence-based guidelines on identifying patients with ALK-rearranged lung cancer using IHC. We retrospectively reviewed 465 resected specimens of non-small cell lung cancer using a tissue microarray as a test set. ALK protein expression using IHC with 5A4 monoclonal antibody (Novocastra) and ALK gene rearrangement using fluorescence in situ hybridization (FISH) with dual-color break-apart probes (Abbott molecular) were examined. Immunoreactivity was scored as 0, 1, 2, or 3, and the results were compared with the FISH results. A diagnostic algorithm was derived from the correlation of the IHC and FISH results and applied to an additional 187 adenocarcinoma samples used as a validation set. In the test set, ALK protein expression was detected in 40 patients (40/465, 8.6%), consisting of IHC scores of 1 (n = 14), 2 (n = 10), and 3 (n = 16), whereas 19 patients (19/453, 4.2%) were FISH-positive. All the FISH-positive patients were assigned IHC scores of 2 or 3. All the patients with ALK IHC scores of 3 were FISH-positive, those with scores of 0 or 1 were FISH-negative, and those with scores of 2 were FISH variable. In the validation set, ALK protein expression was detected in 14 patients (scores of 1, n = 2; scores of 2, n = 6; and scores of 3, n = 6), of which nine patients (9/187, 4.8%) were FISH-positive. All the patients with IHC scores of 0 or 1 were FISH-negative, and those with scores of 3 were FISH- positive. Among the patients with IHC scores of 2, three (3/6, 50%) were FISH-positive. The sensitivity and specificity of IHC was 100% and 95.8%, respectively. These data supported an IHC scoring algorithm in which ALK IHC scores of 0, 1, or 3 were highly compatible with FISH results, and IHC scores of 2 were variable. Based on these findings, the IHC assay using the 5A4 antibody reliably detected non-small cell lung cancer with ALK rearrangement and may be useful as a screening method to identify these tumors.