title: KIF5B/RET fusion gene analysis in a selected series of cytological specimens of EGFR, KRAS and EML4-ALK wild-type adenocarcinomas of the lung.
abstract: A new RET fusion gene has been recently described in a subset of non-small cell lung cancer (NSCLC) identified by specific clinico-pathologic characteristics. This transforming gene arise from the fusion of KIF5B and the RET proto-oncogene, and it is mutually exclusive with EGFR, KRAS and EML4/ALK alterations. For this reason it could represent a putative target for specific inhibitory drugs and its evaluation could be necessary in the future daily molecular characterization of NSCLCs. One of the major challenge in diagnostic molecular pathology is to optimize genotyping tests with the minimally invasive techniques used to acquire diagnostic tumor tissue or cells. This is a significant relevant issue for approximately 60% of NSCLC patients presenting with unresectable disease, where the only pathologic materials available for diagnostic use are small biopsy or cytological specimens. Thus, the aim of this study was to verify the possibility to use RNA purified from cytological specimens to perform KIF5B/RET gene fusion expression analysis. Accordingly, we looked for the presence of the rearrangement in formalin fixed paraffin embedded tissues (FFPETs) and cytological specimens (CSs) of a selected series of "triple-marker" negative adenocarcinomas. The tests conducted revealed the presence of 1 positive patient for variant 1 of KIF5B/RET among the 49 analyzed. The presence of this fusion transcript was found in both FFPET and CS of the same patient demonstrating that the RNA obtained from minimally invasive techniques is perfectly suitable for this kind of tests. The presence of the rearrangement was also confirmed by FISH analysis. In conclusion, our findings confirm that the performance of cytology-based molecular testing for KIF5B/RET rearrangements is at least as effective as histology-based analysis, both with regard to the success rate for nucleic acid isolation and the ability to detect gene alterations.
authors.affiliation: Department of Surgical, Medical, Molecular, and Critical Area Pathology, Division of Pathological Anatomy, University of Pisa, Pisa, Italy.
authors.forename: Nicla
authors.initials: N
authors.lastname: Borrelli
authors.affiliation: Department of Surgical, Medical, Molecular, and Critical Area Pathology, Division of Pathological Anatomy, University of Pisa, Pisa, Italy. Electronic address: riccardo.giannini@dc.unipi.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Giannini
authors.affiliation: Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Proietti
authors.affiliation: Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Greta
authors.initials: G
authors.lastname: Alì
authors.affiliation: Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Pelliccioni
authors.affiliation: Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Niccoli
authors.affiliation: Unit of Thoracic Surgery, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Lucchi
authors.affiliation: Unit of Thoracic Surgery, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Melfi
authors.affiliation: Department of Surgical, Medical, Molecular, and Critical Area Pathology, Division of Thoracic Surgery, University of Pisa, Pisa, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mussi
authors.affiliation: Department of Surgical, Medical, Molecular, and Critical Area Pathology, Division of Pathological Anatomy, University of Pisa, Pisa, Italy; Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.affiliation: Department of Surgical, Medical, Molecular, and Critical Area Pathology, Division of Pathological Anatomy, University of Pisa, Pisa, Italy; Unit of Pathological Anatomy, Azienda Ospedaliera Universitaria Pisana, AOUP, Pisa, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D014178:Translocation, Genetic; D018631:ras Proteins / Q000235:genetics
chemical_list: C522504:EML4-ALK fusion protein, human; C573239:KIF5B-RET fusion protein, human; C117307:KRAS protein, human; C000715470:MAS1 protein, human; D015514:Oncogene Proteins, Fusion; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D066246:ErbB Receptors; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: Adenocarcinoma; Cytology; Fluorescent in situ hybridization; KIF5B/RET rearrangement; Lung; Reverse transcriptase-polymerase chain reaction; Solid