title: Prognostic effect of age on survival of patients with stage I adenocarcinoma of the lung.
abstract: OBJECTIVE
  It is still unclear whether age is an independent prognostic factor in patients with stage I NSCLC.
  
  
  METHODS
  Five hundred and sixty-nine patients with stage I adenocarinoma who underwent surgical resection as first treatment were included. The effect on overall survival of age, gender, smoking habits, Charlson comorbidity index score (CCIS), type of surgery, tumor size and lymphatic or blood vessel invasion was analyzed.
  
  
  RESULTS
  When the patients were divided into four groups according to quartiles of age, distributions of gender, smoking habit, CCIS, histology, blood vessel invasion and adjuvant chemotherapy were significantly different among the four groups. Age, gender, smoking habit, CCIS, tumor size and lymphatic and blood vessel invasion were significantly associated with overall survival of the patients in Kaplan-Meier analysis (logrank, P <0.001, P <0.001, P = 0.029, P <0.001, P = 0.001, P = 0.001 and P = 0.007, respectively). Moreover, the highest quartile of age (over 68 years old) was a prominent determinant for a worse prognosis after adjustment for the confounding variables using a Cox proportional hazard model (adjusted hazard ratio = 2.735, 95% confidence interval = 1.623-4.608, P <0.001).
  
  
  CONCLUSIONS
  The findings suggest that age is an important determinant of overall survival in patients with stage I adenocarcinoma. Therefore, age should be considered in classifying the patients into groups of higher or lower risk for death as well as in designing clinical trials.
authors.affiliation: Center for Lung Cancer and Pulmonary Division, Department of Internal Medicine, Inha University Hospital, Inchon, Korea. jsryu@inha.ac.kr
authors.forename: Jeong-Seon
authors.initials: JS
authors.lastname: Ryu
authors.forename: Chang-Min
authors.initials: CM
authors.lastname: Choi
authors.forename: Seok-Chul
authors.initials: SC
authors.lastname: Yang
authors.forename: Sang-Yun
authors.initials: SY
authors.lastname: Song
authors.forename: Young-June
authors.initials: YJ
authors.lastname: Jeon
authors.forename: Tae-Won
authors.initials: TW
authors.lastname: Jang
authors.forename: Do-Jin
authors.initials: DJ
authors.lastname: Kim
authors.forename: Seung Hun
authors.initials: SH
authors.lastname: Jang
authors.forename: Sei-Hoon
authors.initials: SH
authors.lastname: Yang
authors.forename: Min-Ki
authors.initials: MK
authors.lastname: Lee
authors.forename: Kwan-Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Hyang-Jeong
authors.initials: HJ
authors.lastname: Jo
authors.forename: Se-Jin
authors.initials: SJ
authors.lastname: Jang
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Jae-Hwa
authors.initials: JH
authors.lastname: Cho
authors.forename: Yoo-Duk
authors.initials: YD
authors.lastname: Choi
authors.forename: Hae-Seong
authors.initials: HS
authors.lastname: Nam
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Suh
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000401:mortality* / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000209:etiology / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects