New fluorescence method detects ALK rearrangement in lung cancer patients

Aug. 3, 2011

Fluorescence in situ hybridization (FISH) has been the preferred method for detecting anaplastic lymphoma kinase (ALK) rearrangement in lung cancer patients.

Fluorescence in situ hybridization (FISH) has been the preferred method for detecting anaplastic lymphoma kinase (ALK) rearrangement in lung cancer patients. These particular patients have been found to respond well to crizotinib, an ALK inhibitor currently in clinical trials.

But according to research published in the August issue of the Journal of Thoracic Oncology, FISH requires a fluorescence microscope, and the signals are labile and rapidly fade over time. Led by Jin-Haeng Chung, MD, Ph.D., of Seoul National University Bundang Hospital in South Korea, researchers compared ALK rearrangement assessments using FISH and a newly developed method called chromogenic in situ hybridization (CISH). CISH allows detection of gene copy status using a conventional peroxidase-base reaction and standard brightfield light microscope.

Out of a total of 465 non-small cell lung cancer samples, ALK rearrangement was assessed using CISH in 449 patients (96.6%) and ALK rearrangement was identified in 18 patients (4%). Using FISH, ALK rearrangement was assessed in 453 patients (97.4%); ALK rearrangement was identified in 19 patients (4.2%). Among these cases, 443 cases (95.3%) had results matching the corresponding FISH results: 17 rearranged, 425 wild types, and one discordant case.

"There was high concordance in the assessment of ALK gene rearrangement between FISH and CISH techniques," the researchers wrote.

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Posted by Lee Mather

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