CONTEXT: Echinoderm microtubule-associated proteinlike 4-anaplastic lymphoma kinase (EML4-ALK) gene fusions are detected in 3% to 13% of non-small cell lung carcinomas. Accurate testing for detection of EML4-ALK fusions is essential for appropriate therapy selection. OBJECTIVE: To compare reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) methodologies for detection of EML4-ALK fusions. DESIGN: Forty-six pulmonary adenocarcinomas were selected with enrichment for wild-type epidermal growth factor receptor (EGFR) status (wild type, n = 42; mutant, n = 4). Specimens were tested by IHC (Dako; clone ALK1), FISH (Abbott Molecular; LSI ALK break apart), and RT-PCR (variants 1 and 3a/b). RESULTS: EML4-ALK variant 3a/b was detectable by RT-PCR, FISH, and IHC in 4% (2 of 46) of specimens. Complete agreement among FISH and IHC reviewers was obtained for variant 3a/b. No concordance existed among methodologies for the detection of EML4-ALK variant 1. The RT-PCR method detected variant 1 in 20% (9 of 46) of specimens. Agreement among FISH viewers was poor for variant 1 because only 11% (1/9) of specimens were scored as positive by all 3 viewers. The sensitivity of IHC for detection of variant 1 was also poor because only 1 of 9 samples (11%) was scored as positive. Overall, the frequency of EML4-ALK variants 1 and 3a/b was 24% (11 of 46) in adenocarcinomas enriched for wild-type EGFR status. One EML4-ALK variant 1 fusion was found to coexist with an EGFR exon 21 mutation. CONCLUSIONS: The FISH interpretation demonstrated great variability among observers. The RT-PCR method was the most sensitive and least-subjective methodology for detection of EML4-ALK fusions.
CONTEXT: Echinoderm microtubule-associated proteinlike 4-anaplastic lymphoma kinase (EML4-ALK) gene fusions are detected in 3% to 13% of non-small cell lung carcinomas. Accurate testing for detection of EML4-ALK fusions is essential for appropriate therapy selection. OBJECTIVE: To compare reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) methodologies for detection of EML4-ALK fusions. DESIGN: Forty-six pulmonary adenocarcinomas were selected with enrichment for wild-type epidermal growth factor receptor (EGFR) status (wild type, n = 42; mutant, n = 4). Specimens were tested by IHC (Dako; clone ALK1), FISH (Abbott Molecular; LSI ALK break apart), and RT-PCR (variants 1 and 3a/b). RESULTS: EML4-ALK variant 3a/b was detectable by RT-PCR, FISH, and IHC in 4% (2 of 46) of specimens. Complete agreement among FISH and IHC reviewers was obtained for variant 3a/b. No concordance existed among methodologies for the detection of EML4-ALK variant 1. The RT-PCR method detected variant 1 in 20% (9 of 46) of specimens. Agreement among FISH viewers was poor for variant 1 because only 11% (1/9) of specimens were scored as positive by all 3 viewers. The sensitivity of IHC for detection of variant 1 was also poor because only 1 of 9 samples (11%) was scored as positive. Overall, the frequency of EML4-ALK variants 1 and 3a/b was 24% (11 of 46) in adenocarcinomas enriched for wild-type EGFR status. One EML4-ALK variant 1 fusion was found to coexist with an EGFR exon 21 mutation. CONCLUSIONS: The FISH interpretation demonstrated great variability among observers. The RT-PCR method was the most sensitive and least-subjective methodology for detection of EML4-ALK fusions.
Authors: Christian Rolfo; Francesco Passiglia; Marta Castiglia; Luis E Raez; Paul Germonpre; Ignacio Gil-Bazo; Karen Zwaenepoel; Annemieke De Wilde; Giuseppe Bronte; Antonio Russo; Jan P Van Meerbeeck; Paul Van Schil; Patrick Pauwels Journal: Transl Lung Cancer Res Date: 2014-08
Authors: Hans Brunnström; Anna Johansson; Sofia Westbom-Fremer; Max Backman; Dijana Djureinovic; Annika Patthey; Martin Isaksson-Mettävainio; Miklos Gulyas; Patrick Micke Journal: Mod Pathol Date: 2017-06-30 Impact factor: 7.842
Authors: Lester J Layfield; Sinchita Roy-Chowdhuri; Zubair Baloch; Hormoz Ehya; Kim Geisinger; Susan J Hsiao; Oscar Lin; Neal I Lindeman; Michael Roh; Fernando Schmitt; Nikoletta Sidiropoulos; Paul A VanderLaan Journal: Diagn Cytopathol Date: 2016-08-26 Impact factor: 1.582
Authors: Lynette M Sholl; Stanislawa Weremowicz; Stacy W Gray; Kwok-Kin Wong; Lucian R Chirieac; Neal I Lindeman; Jason L Hornick Journal: J Thorac Oncol Date: 2013-03 Impact factor: 15.609