title: Withholding stereotactic radiotherapy in elderly patients with stage I non-small cell lung cancer and co-existing COPD is not justified: outcomes of a Markov model analysis.
abstract: OBJECTIVE
  To model outcomes of SBRT versus best supportive care (BSC) in elderly COPD patients with stage I NSCLC.
  
  
  METHODS
  A Markov model was constructed to simulate the quality-adjusted and overall survival (OS) in patients ⩾75years undergoing either SBRT or BSC for a five-year timeframe. SBRT rates of local, regional and distant recurrences were obtained from 247 patients treated at the VUMC, Amsterdam. Recurrence rates were converted into transition probabilities and stratified into four groups according to T stage (1, 2) and COPD GOLD score (I-II, III-IV). Data for untreated patients were obtained from the California Cancer Registry. Tumor stage and GOLD score utilities were adapted from the literature.
  
  
  RESULTS
  Our model correlated closely with the source OS data for SBRT treated and untreated patients. After SBRT, our model predicted for 6.8-47.2% five-year OS and 14.9-27.4 quality adjusted life months (QALMs). The model predicted for 9.0% and 2.8% five-year OS, and 10.1 and 6.1 QALMs for untreated T1 and T2 patients, respectively. The benefit of SBRT was the least for T2, GOLD III-IV patients.
  
  
  CONCLUSIONS
  Our model indicates that SBRT should be considered in elderly stage I NSCLC patients with COPD.
authors.affiliation: Department of Radiation Oncology, London Regional Cancer Program, London, Canada.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Louie
authors.forename: George
authors.initials: G
authors.lastname: Rodrigues
authors.forename: Malek
authors.initials: M
authors.lastname: Hannouf
authors.forename: Frank
authors.initials: F
authors.lastname: Lagerwaard
authors.forename: David
authors.initials: D
authors.lastname: Palma
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Zaric
authors.forename: Cornelis
authors.initials: C
authors.lastname: Haasbeek
authors.forename: Suresh
authors.initials: S
authors.lastname: Senan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008390:Markov Chains; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D019057:Quality-Adjusted Life Years; D016634:Radiosurgery / Q000379:methods*; D015996:Survival Rate; D028761:Withholding Treatment