title: Time-varying pattern of postoperative recurrence risk of early-stage (T1a-T2bN0M0) non-small cell lung cancer (NSCLC): results of a single-center study of 994 Chinese patients.
abstract: BACKGROUND
  The aim of this study was to analyze the time-varying pattern of recurrence risk of early-stage (T1a-T2bN0M0) non-small cell lung cancer (NSCLC) after surgery using the hazard function and identify patients who might benefit from adjuvant chemotherapy.
  
  
  METHODS
  This retrospective study enrolled 994 patients with early-stage NSCLC who underwent radical surgical resection between January 1999 and October 2009. Survival curves were generated using the Kaplan-Meier method, and the annual recurrence hazard was estimated using the hazard function.
  
  
  RESULTS
  The median recurrence-free survival (RFS) was 8.8 years. The life table survival analysis showed that the 1-year, 3-year, 5-year and 10-year recurrence rates were 82.0%, 67.0%, 59.0% and 48.0%, respectively. Approximately 256 (25.7%) patients experienced relapse [locoregional: 32 (3.2%) and distant: 224 (22.5%)], and 162 patients died from cancer. The annual recurrence hazard curve for the entire population showed that the first major recurrence surge reached a maximum 1.6 years after surgery. The curve subsequently declined until reaching a nadir at 7.2 years. A second peak occurred at 8.8 years. An analysis of clinical-pathological factors demonstrated that this double-peaked pattern was present in several subgroups.
  
  
  CONCLUSIONS
  The presence of a double-peaked pattern indicates that there is a predictable temporal distribution of the recurrence hazard of early-stage NSCLC. The annual recurrence hazard may be an effective method of selecting patients at high risk of recurrence, who may benefit from adjuvant therapy.
authors.affiliation: Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China; Shaanxi Provincial People's Hospital, Xi'an, Shaanxi, China.
authors.forename: Jian-fei
authors.initials: JF
authors.lastname: Zhu
authors.affiliation: Department of Gastro-pancreatic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Xing-yu
authors.initials: XY
authors.lastname: Feng
authors.affiliation: Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Xue-wen
authors.initials: XW
authors.lastname: Zhang
authors.affiliation: Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Ying-sheng
authors.initials: YS
authors.lastname: Wen
authors.affiliation: Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lin
authors.affiliation: Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Tie-hua
authors.initials: TH
authors.lastname: Rong
authors.affiliation: Department of Radiation-Oncology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Cai
authors.affiliation: Department of Thoracic Surgery, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
authors.forename: Lan-jun
authors.initials: LJ
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D002681:China; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011184:Postoperative Period; D012008:Recurrence; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis; D013997:Time Factors