title: Propensity score-matched analysis of comprehensive local therapy for oligometastatic non-small cell lung cancer that did not progress after front-line chemotherapy.
abstract: OBJECTIVE
  To retrospectively analyze factors influencing survival in patients with non-small cell lung cancer presenting with ≤3 synchronous metastatic lesions.
  
  
  METHODS
  We identified 90 patients presenting between 1998 and 2012 with non-small cell lung cancer and ≤3 metastatic lesions who had received at least 2 cycles of chemotherapy followed by surgery or radiation therapy before disease progression. The median number of chemotherapy cycles before comprehensive local therapy (CLT) (including concurrent chemoradiation as first-line therapy) was 6. Factors potentially affecting overall (OS) or progression-free survival (PFS) were evaluated with Cox proportional hazards regression. Propensity score matching was used to assess the efficacy of CLT.
  
  
  RESULTS
  Median follow-up time was 46.6 months. Benefits in OS (27.1 vs 13.1 months) and PFS (11.3 months vs 8.0 months) were found with CLT, and the differences were statistically significant when propensity score matching was used (P ≤ .01). On adjusted analysis, CLT had a statistically significant benefit in terms of OS (hazard ratio, 0.37; 95% confidence interval, 0.20-0.70; P ≤ .01) but not PFS (P=.10). In an adjusted subgroup analysis of patients receiving CLT, favorable performance status (hazard ratio, 0.43; 95% confidence interval, 0.22-0.84; P=.01) was found to predict improved OS.
  
  
  CONCLUSIONS
  Comprehensive local therapy was associated with improved OS in an adjusted analysis and seemed to favorably influence OS and PFS when factors such as N status, number of metastatic lesions, and disease sites were controlled for with propensity score-matched analysis. Patients with favorable performance status had improved outcomes with CLT. Ultimately, prospective, randomized trials are needed to provide definitive evidence as to the optimal treatment approach for this patient population.
authors.affiliation: University of Texas School of Public Health, Houston, Texas; Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Tommy
authors.initials: T
authors.lastname: Sheu
authors.affiliation: Department of Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: John V
authors.initials: JV
authors.lastname: Heymach
authors.affiliation: Department of Thoracic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Swisher
authors.affiliation: Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Rao
authors.affiliation: Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Weinberg
authors.affiliation: Department of Thoracic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Reza
authors.initials: R
authors.lastname: Mehran
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Mary Frances
authors.initials: MF
authors.lastname: McAleer
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Zhongxing
authors.initials: Z
authors.lastname: Liao
authors.affiliation: Department of Gastrointestinal Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Aloia
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. Electronic address: dgomez@mdanderson.org.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gomez
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000556:secondary / Q000628:therapy; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D059248:Chemoradiotherapy / Q000379:methods; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy; D057216:Propensity Score; D016634:Radiosurgery / Q000379:methods; D012189:Retrospective Studies; D012737:Sex Factors