title: Clinical heterogeneity of extranodal NK/T-cell lymphoma, nasal type: a national survey of the Korean Cancer Study Group.
abstract: BACKGROUND
  This national survey was undertaken to propose the classification of extranodal natural killer (NK)/T-cell lymphoma (NTCL) subtypes and to clarify a clinical heterogeneity.
  
  
  METHODS
  Two hundred and eighty patients newly diagnosed as NTCL were enrolled from 22 Korean medical centers. Two subsets were compared: one involving the upper aerodigestive tract (UAT) and another involving the non-upper aerodigestive tract (NUAT) region, which comprises the skin, gastrointestinal tract, and liver or soft tissues. Clinical prognostic factors, survival outcomes, and independent predictors for survival were compared between each subset.
  
  
  RESULTS
  NUAT-NTCL (59 patients) had significantly higher proportions of disseminated disease, aggressive biologic features, and unfavorable host reactions compared with UAT-NTCL (221 patients). NUAT-NTCL had shortened 5-year overall survival (OS) (22% versus 41%, P = 0.001). Ann Arbor staging, the International Prognostic Index, and the NTCL prognostic index failed to predict the OS of NUAT-NTCL, but did predict the OS in UAT-NTCL. Independent predictors for OS by multivariate analyses differed between each subset. In the NUAT subset, extranodal sites and regional nodes predicted the OS, while Ann Arbor staging, age, performance status, and lactate dehydrogenase level predicted the OS in the UAT subset.
  
  
  CONCLUSIONS
  NUAT-NTCL may represent a distinctive disease entity in terms of clinical factors, independent predictors, and survival outcomes.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine.
authors.forename: T M
authors.initials: TM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Pathology, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine.
authors.forename: Y K
authors.initials: YK
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, Korea Cancer Center Hospital, Seoul.
authors.forename: B-Y
authors.initials: BY
authors.lastname: Ryoo
authors.affiliation: Department of Internal Medicine, Busan National University College of Medicine, Busan.
authors.forename: G J
authors.initials: GJ
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, College of Medicine, Catholic University, Seoul.
authors.forename: Y S
authors.initials: YS
authors.lastname: Hong
authors.affiliation: Department of Internal Medicine, Dong-A University Medical Center, Busan.
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inha University College of Medicine, Incheon.
authors.forename: C S
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chungnam National University College of Medicine, Daejon.
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul.
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Kyungbook National University College of Medicine, Daegu.
authors.forename: S K
authors.initials: SK
authors.lastname: Sohn
authors.affiliation: Department of Internal Medicine, Hallym University College of Medicine, Seoul.
authors.forename: H H
authors.initials: HH
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Fatima Hospital, Daegu.
authors.forename: J L
authors.initials: JL
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Asan Medical Center, Ulsan University College of Medicine, Seoul.
authors.forename: Y K
authors.initials: YK
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Chonbuk National University College of Medicine, Chonju.
authors.forename: C Y
authors.initials: CY
authors.lastname: Yim
authors.affiliation: Department of Internal Medicine, Gyeongsang National University Hospital, Jinju.
authors.forename: W S
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University Paik Hospital, Seoul, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Yuh
authors.affiliation: Department of Pathology, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine.
authors.forename: C W
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Cancer Research Institute, Seoul National University College of Medicine. Electronic address: heo1013@snu.ac.kr.
authors.forename: D S
authors.initials: DS
authors.lastname: Heo
mesh_terms: D005260:Female; D006258:Head and Neck Neoplasms / Q000145:classification / Q000473:pathology; D006801:Humans; D054391:Lymphoma, Extranodal NK-T-Cell / Q000145:classification* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009669:Nose Neoplasms / Q000145:classification* / Q000473:pathology; D011379:Prognosis