title: Increasing Rates of No Treatment in Advanced-Stage Non-Small Cell Lung Cancer Patients: A Propensity-Matched Analysis.
abstract: Variation in treatment and survival outcomes for NSCLC is high among patients with stage III or IV disease, but patients with untreated NSCLC have not been critically analyzed to evaluate for improvable outcomes. We evaluated treatment trends and their association with oncologic outcomes for NSCLC, hypothesizing that there are a substantial number of untreated patients who are similar to patients who undergo treatment.
  
  
  
  Linear regression was used to calculate trends in utilization of treatment. Kaplan-Meier and Cox regression modeling were used to determine predictors of receiving treatment. Propensity matching was used to compare survival among subsets of treated versus untreated patients.
  
  
  
  Patients with primary NSCLC were identified from the National Cancer Data base from 1998 to 2012, and 21% of patients (190,539) received no treatment. For stage IIIA and IV, the proportion of untreated patients increased over the study period by 0.21% and 0.4%, respectively (p = 0.003 and p < 0.0001). Regardless of stage, untreated patients had significantly shorter overall survival (OS) (p < 0.0001). Propensity-matched analyses of 6144 stage IIIA patient pairs treated with chemoradiation versus no treatment confirmed shorter OS for untreated patients (median 16.5 versus 6.1 months, p < 0.0001). For 19,046 stage IV patient pairs treated with chemotherapy versus no treatment, similar results were obtained (median OS 9.3 versus 2.0 months, p < 0.0001).
  
  
  
  The proportion of untreated patients with stage IIIA and IV disease is increasing. Survival outcomes among patients with advanced-stage disease are superior with treatment, independent of selection bias. The benefits and risks of treatment should be carefully assessed before choosing to forego treatment.
authors.affiliation: Section of General Thoracic Surgery and Outcomes Research Group, Department of Surgery, University of California Davis Medical Center, Sacramento, California; Heart Lung Vascular Center, David Grant Medical Center, Travis Air Force Base, California. Electronic address: Eadavid@ucdavis.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: David
authors.affiliation: Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, California.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Daly
authors.affiliation: Department of Public Health Sciences, University of California Davis School of Medicine, Davis, California.
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.affiliation: Department of Statistics, University of California Davis, Davis, California.
authors.forename: Chi-Lu
authors.initials: CL
authors.lastname: Chiu
authors.affiliation: Section of General Thoracic Surgery and Outcomes Research Group, Department of Surgery, University of California Davis Medical Center, Sacramento, California.
authors.forename: David T
authors.initials: DT
authors.lastname: Cooke
authors.affiliation: Section of General Thoracic Surgery and Outcomes Research Group, Department of Surgery, University of California Davis Medical Center, Sacramento, California.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Brown
authors.affiliation: Center for Healthcare Policy and Research, University of California Davis, Sacramento, California.
authors.forename: Joy
authors.initials: J
authors.lastname: Melnikow
authors.affiliation: Department of Internal Medicine, University of California Davis Comprehensive Cancer Center, Sacramento, California.
authors.forename: Karen
authors.initials: K
authors.lastname: Kelly
authors.affiliation: Division of Surgical Oncology and Outcomes Research Group, Department of Surgery, University of California Davis Medical Center, Sacramento, California.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Canter
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D016555:Matched-Pair Analysis; D009367:Neoplasm Staging; D057216:Propensity Score; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Chemotherapy; NSCLC; Natural history; Radiation; Surgery; Untreated