title: Are there imaging characteristics associated with lung adenocarcinomas harboring ALK rearrangements?
abstract: BACKGROUND
  5% of lung adenocarcinomas harbor rearrangements of the anaplastic lymphoma kinase (ALK) gene. This study compared computed tomography (CT) imaging features in patients with ALK rearrangements and those with EGFR mutations.
  
  
  METHODS
  30 patients with ALK rearrangements were studied. 97 patients with epidermal growth factor receptor (EGFR) mutations were used as controls. Features assessed included size and location of thoracic lymphadenopathy, and the size, contour, consistency and location of the primary tumor.
  
  
  RESULTS
  127 lung adenocarcinomas were examined. 30 (24%) tumors harbored ALK rearrangements, 97 (76%) tumors harbored EGFR mutations. ALK tumors had larger thoracic lymphadenopathy than the control group (p=0.005). Both readers identified 17 (57%) patients in the ALK group with lymph nodes >1.5cm. Reader 1 identified 19 (20%) patients in the EGFR group with lymph nodes >1.5cm, and reader 2 identified 18 (19%) (kappa 0.969). Patients with ALK rearrangements were more likely to have multifocal lymphadenopathy. Reader 1 identified 22 (73%) ALK patients versus 35 (36%) EGFR patients with multifocal thoracic nodal enlargement, while reader 2 identified 20 (67%) ALK patients versus 30 (31%) EGFR patients (kappa 0.953). 92% of ALK positive lesions were solid.
  
  
  CONCLUSIONS
  ALK positive lung adenocarcinomas are more likely than EGFR mutant lung adenocarcinomas to be associated with larger volume, multifocal thoracic lymphadenopathy. While routine testing for ALK should be standard, the presence of such characteristics in a solid tumor should further prompt testing for ALK rearrangement.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Darragh F
authors.initials: DF
authors.lastname: Halpenny
authors.affiliation: Thoracic Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Riely
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Sara
authors.initials: S
authors.lastname: Hayes
authors.affiliation: Thoracic Oncology Service, Division of Solid Tumor Oncology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Helena
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Junting
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, United States.
authors.forename: Chaya S
authors.initials: CS
authors.lastname: Moskowitz
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, United States. Electronic address: ginsberm@MSKCC.ORG.
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Ginsberg
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000235:genetics*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases
keywords: Anaplastic lymphoma kinase; Computed tomography; Lung adenocarcinoma; Mutation; Radiogenomics; Radiology