title: Comparison of Segmentectomy and Lobectomy in Stage IA Adenocarcinomas.
abstract: Recent studies have suggested that segmentectomy may be an acceptable alternative treatment to lobectomy for surgical management of smaller lung adenocarcinomas. The objective of this study was to compare survival after lobectomy and segmentectomy among patients with pathological stage IA adenocarcinoma categorized as stage T1b (>0 to ≤20 mm) according to the new eighth edition of the TNM system.
  
  
  
  In total, 7989 patients were identified from the Surveillance, Epidemiology, and End Results registry. Propensity scores generated from logistic regression on preoperative characteristics were used to balance the selection bias of undergoing segmentectomy. Overall and lung cancer-specific survival rates of patients undergoing segmentectomy and lobectomy were compared in propensity score-matched groups.
  
  
  
  Overall, 564 patients (7.1%) underwent segmentectomy. Lobectomy led to better overall and lung cancer-specific survival than segmentectomy for the entire cohort (log-rank p < 0.01). After 1:2 propensity score matching, segmentectomy (n = 552) was no longer associated with significantly worse overall survival (5-year survival = 74.45% versus 76.67%, hazard ratio = 1.09, 95% confidence interval: 0.90-1.33) or lung cancer-specific survival (5-year survival = 83.89% versus 86.11%, hazard ratio = 1.12, 95% confidence interval: 0.86-1.46) compared with lobectomy (n = 1085) after adjustment for age, sex, lymph node quantity, and histological subtype. Similar negative findings were identified when patients were stratified according to sex, age, histological subtype, and number of evaluated lymph nodes.
  
  
  
  Patients who underwent segmentectomy may have survival outcomes no different than those of some patients who received lobectomy for pathological stage IA adenocarcinomas at least 10 but no larger than 20 mm in size. These results should be further confirmed through prospective randomized trials.
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Ze-Rui
authors.initials: ZR
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Oncology in Southern China, Collaborative Innovation Centre for Cancer Medicine, and Department of Thoracic Surgery, Sun Yat-Sen University Cancer Centre, Guangzhou, People's Republic of China.
authors.forename: Dong-Rong
authors.initials: DR
authors.lastname: Situ
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Rainbow W H
authors.initials: RWH
authors.lastname: Lau
authors.affiliation: Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Tony S K
authors.initials: TSK
authors.lastname: Mok
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: George G
authors.initials: GG
authors.lastname: Chen
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Underwood
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China. Electronic address: calvinng@surgery.cuhk.edu.hk.
authors.forename: Calvin S H
authors.initials: CSH
authors.lastname: Ng
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011013:Pneumonectomy / Q000379:methods*; D016016:Proportional Hazards Models; D018426:SEER Program; D015996:Survival Rate; D047368:Tumor Burden; D014481:United States / Q000453:epidemiology
keywords: Adenocarcinoma; Eighth TNM system; Lobectomy; Segmentectomy