title: The analysis of ALK gene rearrangement by fluorescence in situ hybridization in non-small cell lung cancer patients.
abstract: BACKGROUND
  ALK gene rearrangement is observed in a small subset (3-7%) of non-small cell lung cancer (NSCLC) patients. The efficacy of crizotinib was shown in lung cancer patients harbouring ALK rearrangement. Nowadays, the analysis of ALK gene rearrangement is added to molecular examination of predictive factors.
  
  
  OBJECTIVE
  The frequency of ALK gene rearrangement as well as the type of its irregularity was analysed by fluorescence in situ hybridisation (FISH) in tissue samples from NSCLC patients.
  
  
  METHODS
  The ALK gene rearrangement was analysed in 71 samples including 53 histological and 18 cytological samples. The analysis could be performed in 56 cases (78.87%), significantly more frequently in histological than in cytological materials. The encountered problem with ALK rearrangement diagnosis resulted from the scarcity of tumour cells in cytological samples, high background fluorescence noises and fragmentation of cell nuclei.
  
  
  RESULTS
  The normal ALK copy number without gene rearrangement was observed in 26 (36.62%) patients ALK gene polysomy without gene rearrangement was observed in 25 (35.21%) samples while in 3 (4.23%) samples ALK gene amplification was found. ALK gene rearrangement was observed in 2 (2.82%) samples from males, while in the first case the rearrangement coexisted with ALK amplification. In the second case, signet-ring tumour cells were found during histopathological examination and this patient was successfully treated with crizotinib with partial remission lasting 16 months.
  
  
  CONCLUSIONS
  FISH is a useful technique for ALK gene rearrangement analysis which allows us to specify the type of gene irregularities. ALK gene examination could be performed in histological as well as cytological (cellblocks) samples, but obtaining a reliable result in cytological samples depends on the cellularity of examined materials.
authors.affiliation: Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Poland.
authors.forename: Kamila
authors.initials: K
authors.lastname: Wojas-Krawczyk
authors.affiliation: Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Poland.
authors.forename: Paweł Adam
authors.initials: PA
authors.lastname: Krawczyk
authors.affiliation: Wielkopolska Center of Pulmonology and Thoracosurgery, Poznan, Poland.
authors.forename: Rodryg Adam
authors.initials: RA
authors.lastname: Ramlau
authors.affiliation: Department of Clinical Pathomorphology, Medical University of Lublin, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Szumiło
authors.affiliation: Autonomous Public Clinical Hospital No. 3, Medical University of Silesia, Katowice, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kozielski
authors.affiliation: Department of Chemotherapy with Division of Cancer Diagnosis and Treatment, Copernicus Memorial Hospital in Lodz, Regional Oncology Center, Lodz, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kalinka-Warzocha
authors.affiliation: Wielkopolska Center of Pulmonology and Thoracosurgery, Poznan, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Bryl
authors.affiliation: Department of Pathomorphology, Dr. Władysław Biegański Regional Specialist Hospital, Lodz, Poland.
authors.forename: Alina
authors.initials: A
authors.lastname: Knopik-Dąbrowicz
authors.affiliation: Wielkopolska Center of Pulmonology and Thoracosurgery, Poznan, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Spychalski
authors.affiliation: 3 Department of Lung Diseases, Oncological Division, Mazovian Centre for Treatment of Lung Diseases and Tuberculosis, Otwock, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Szczęsna
authors.affiliation: Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Rydzik
authors.affiliation: Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Milanowski
keywords: ALK gene rearrangement; crizotinib; fluorescence in situ hybridization; non-small cell lung cancer