title: Clinicoradiologic characteristics of patients with lung adenocarcinoma harboring EML4-ALK fusion oncogene.
abstract: BACKGROUND
  The fusion oncogene of echinoderm microtubule-associated protein like 4 (EML4) and anaplastic lymphoma kinase (ALK) defines a new molecular subset of non-small-cell lung cancer. We explored the EML4-ALK gene in a relatively large cohort and reviewed the clinicoradiologic background of the patients.
  
  
  METHODS
  We studied 720 patients with lung adenocarcinoma. The clinicopathological characteristics of each patient were compared among the subgroups stratified by the EML4-ALK gene status. For radiographic evaluation, we scored the proportion of the ground-glass opacity (GGO) component and calculated the tumor disappearance rate (TDR) in each tumor in the cohort of 168 patients that were extracted by using a case-matching procedure.
  
  
  RESULTS
  Twenty-eight (3.9%) patients harbored the EML4-ALK gene. Younger age (p=0.001), no or light history of smoking (p=0.05) and normal serum carcinoembryonic antigen (CEA) level (p=0.04) were characteristics of the patients with EML4-ALK. No significant difference was observed for overall and disease free survival between the two groups. All but one tumor in the EML4-ALK-positive group exhibited no GGO, whereas half of the tumors (69/140 patients) in the EML4-ALK-negative group exhibited some GGO (p=0.0004). The mean TDRs were 0.33 and 0.54, respectively, which was significantly lower in the positive group (p=0.0006).
  
  
  CONCLUSIONS
  We identified younger age, no or light history of smoking, and normal serum CEA as clinical features of patients with EML4-ALK-positive lung adenocarcinoma. In addition, EML4-ALK-positive tumors exhibited a solid pattern on CT. These features may be of value in predicting for patient selection for ALK inhibition therapy in the absence of genetic screening.
authors.affiliation: Department of Thoracic Surgery, Aichi Cancer Center Hospital, Nagoya, Japan. tfukui@aichi-cc.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fukui
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kenji
authors.initials: K
authors.lastname: Tomizawa
authors.forename: Simon
authors.initials: S
authors.lastname: Ito
authors.forename: Shunzo
authors.initials: S
authors.lastname: Hatooka
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mitsudomi
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000401:mortality; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D002272:Carcinoembryonic Antigen; C522504:EML4-ALK fusion protein, human; D015514:Oncogene Proteins, Fusion