title: Effect of Adjuvant Chemotherapy after Complete Resection for Pathologic Stage IB Lung Adenocarcinoma in High-Risk Patients as Defined by a New Recurrence Risk Scoring Model.
abstract: OBJECTIVE
  We conducted a retrospective analysis to determine if adjuvant chemotherapy prolongs overall survival in patients with pathologic stage IB lung adenocarcinoma who had undergone complete resection and were defined as high-risk by a newly developed recurrence risk scoring model.
  
  
  METHODS
  Patients who underwent curative resection for stage IB lung adenocarcinoma were analyzed with a newly developed recurrence risk scoring model and divided into a low-risk group and a high-risk group. The patients in the high-risk group were retrospectively divided into two groups based on whether they underwent adjuvant chemotherapy or observation. Recurrence-free survival and overall survival were compared between these two groups.
  
  
  RESULTS
  A total of 328 patients who underwent curative resection between 2000 and 2009 were included in this study, of whom 110 (34%) received adjuvant chemotherapy and 218 (67%) underwent observation without additional treatment. According to our risk model, 167 patients (51%) were high-risk and 161 (49%) were low-risk. The 5-year recurrence-free survival rates and overall survival were 84.4% and 91.5% in low-risk patients and 53.9% and 74.7% in high-risk patients (p < 0.001). In high-risk patients, the 5-year overall survival rates were 77% among patients who underwent observation and 87% among those who underwent adjuvant chemotherapy (p=0.019).
  
  
  CONCLUSIONS
  Adjuvant chemotherapy prolonged overall survival among high-risk patients who had undergone complete resection for stage IB lung adenocarcinoma.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyo Joon
authors.initials: HJ
authors.lastname: Jang
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sukki
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kwhanmien
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Thoracic and Cardiovascular Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sanghoon
authors.initials: S
authors.lastname: Jheon
authors.affiliation: Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Hee Chul
authors.initials: HC
authors.lastname: Yang
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, Seoul, Korea.
authors.forename: Dong Kwan
authors.initials: DK
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D011182:Postoperative Care; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Adenocarcinoma; Adjuvant chemotherapy; High risk; Stage IB