title: Definitive primary therapy in patients presenting with oligometastatic non-small cell lung cancer.
abstract: OBJECTIVE
  Although palliative chemotherapy is the standard of care for patients with diagnoses of stage IV non-small cell lung cancer (NSCLC), patients with a small metastatic burden, "oligometastatic" disease, may benefit from more aggressive local therapy.
  
  
  METHODS
  We identified 186 patients (26% of stage IV patients) prospectively enrolled in our institutional database from 2002 to 2012 with oligometastatic disease, which we defined as 5 or fewer distant metastatic lesions at diagnosis. Univariate and multivariable Cox proportional hazards models were used to identify patient and disease factors associated with improved survival. Using propensity score methods, we investigated the effect of definitive local therapy to the primary tumor on overall survival.
  
  
  RESULTS
  Median age at diagnosis was 61 years of age; 51% of patients were female; 12% had squamous histology; and 33% had N0-1 disease. On multivariable analysis, Eastern Cooperate Oncology Group performance status ≥ 2 (hazard ratio [HR], 2.43), nodal status, N2-3 (HR, 2.16), squamous pathology, and metastases to multiple organs (HR, 2.11) were associated with a greater hazard of death (all P<.01). The number of metastatic lesions and radiologic size of the primary tumor were not significantly associated with overall survival. Definitive local therapy to the primary tumor was associated with prolonged survival (HR, 0.65, P=.043).
  
  
  CONCLUSIONS
  Definitive local therapy to the primary tumor appears to be associated with improved survival in patients with oligometastatic NSCLC. Select patient and tumor characteristics, including good performance status, nonsquamous histology, and limited nodal disease, may predict for improved survival in these patients.
authors.affiliation: Harvard Medical School, Boston, Massachusetts.
authors.forename: Ravi B
authors.initials: RB
authors.lastname: Parikh
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Angel M
authors.initials: AM
authors.lastname: Cronin
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: David E
authors.initials: DE
authors.lastname: Kozono
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Oxnard
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Mak
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: David M
authors.initials: DM
authors.lastname: Jackman
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Lo
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Baldini
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Johnson
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts; Brigham and Women's Hospital, Boston, Massachusetts. Electronic address: achen@lroc.harvard.edu.
authors.forename: Aileen B
authors.initials: AB
authors.lastname: Chen
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy; D000368:Aged; D000704:Analysis of Variance; D001859:Bone Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary / Q000628:therapy; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000628:therapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000556:secondary / Q000628:therapy; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D057216:Propensity Score; D011859:Radiography; D012189:Retrospective Studies; D012720:Severity of Illness Index