title: Factors involved in lymph node metastasis in clinical stage I non-small cell lung cancer--from studies of 604 surgical cases.
abstract: OBJECTIVE
  To identify the factors involved in lymph node metastasis, 604 clinical stage I non-small cell lung cancer cases were studied.
  
  
  METHODS
  Age, sex, Brinkmann Index (BI), histopathological type, histopathological differentiation degree, tumor size and CEA value were studied as factors involved in lymph node metastasis for 604 cases that were diagnosed to be clinical stage I (T1-T2N0M0; 1997 TNM categorization) non-small cell lung cancer.
  
  
  RESULTS
  Lymph node metastasis was observed in 161 cases (27%). The factors involved in lymph node metastasis included the degree of histopathological differentiation and the tumor size. While the metastasis rate was less than 10% in well-differentiated cancers (even when the tumor size exceeded 4cm), in moderately differentiated and poorly differentiated cancers, the lymph node metastasis rate increased in proportion to tumor size.
  
  
  CONCLUSIONS
  In stage I non-small cell lung cancer cases, cases with a low probability of lymph node metastasis are well-differentiated cancers. In these cases, lymph node dissection may be omitted in surgery (reduction surgery), and such cases may thus be good subjects for undergoing either stereotactic body radiotherapy (SBRT) or particle therapy.
authors.affiliation: Department of Radiation Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusaku, Nagoya 464-0021, Japan. 101348@acc.pref.aichi.jp
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Fuwa
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mitsudomi
authors.forename: Takashi
authors.initials: T
authors.lastname: Daimon
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shinoda
authors.forename: Shunzou
authors.initials: S
authors.lastname: Hatooka
authors.forename: Schuichi
authors.initials: S
authors.lastname: Mori
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fukui
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Inaba
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis
chemical_list: D002272:Carcinoembryonic Antigen