title: Prognostic implication of pulmonary function at the beginning of postoperative radiotherapy in non-small cell lung cancer.
abstract: OBJECTIVE
  The purpose of this study was to investigate the prognostic effect of pulmonary function at the beginning of postoperative radiotherapy (PORT) in non-small cell lung cancer (NSCLC).
  
  
  METHODS
  From January 2002 to December 2012, 115 patients with NSCLC who underwent PORT and took the forced expiratory volume in 1 second (FEV1) at the beginning of PORT were analysed. PORT began within 4-6weeks following surgery, and the 3-dimensional conformal technique was used with conventional fractionation. The high and low FEV1 groups were divided by the median absolute value of FEV1 at the beginning of PORT, and we compared the clinical factors and survival between two groups.
  
  
  RESULTS
  The median absolute value of FEV1 at the beginning of PORT was 1.68L (range, 0.83-3.89), and patients were divided into low and high FEV1 groups (<1.68L versus ⩾1.68L). Patients in the low FEV1 group showed a lower preoperative FEV1 (mean, 1.94L versus 2.73L, p<0.001) and received more pneumonectomy (36.8% versus 8.6%, p<0.001) compared to the high FEV1 group. The overall median follow-up time was 31months (range, 3-110), and 5-year locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 52.4%, 48.9%, and 45.9%, respectively. Five-year OS of the low FEV1 group was significantly lower than that of the high FEV1 group (35.4% versus 56.9%, p=0.002), and no significant differences were found in LRRFS and DMFS. In a multivariate analysis, the difference of OS between the low and high FEV1 groups remained significant (Hazard Ratio=2.04, CI, 1.18-3.55, p=0.011).
  
  
  CONCLUSIONS
  The FEV1 at the beginning of PORT was an independent significant prognostic factor in patients with NSCLC who received PORT. Considering this analysis was limited to only patients receiving PORT, further studies are warranted to compare the survival effect of postoperative pulmonary function between groups with/without PORT.
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Hwanik
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, USA; BIO5 Institute, The University of Arizona, Tucson, USA; Leon Levy Cancer Center, The University of Arizona, Tucson, USA.
authors.forename: Yves A
authors.initials: YA
authors.lastname: Lussier
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea; Department of Medicine, The University of Arizona, Tucson, USA; BIO5 Institute, The University of Arizona, Tucson, USA; Leon Levy Cancer Center, The University of Arizona, Tucson, USA. Electronic address: okyu.noh@gmail.com.
authors.forename: O Kyu
authors.initials: OK
authors.lastname: Noh
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, USA; BIO5 Institute, The University of Arizona, Tucson, USA; Leon Levy Cancer Center, The University of Arizona, Tucson, USA.
authors.forename: Haiquan
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Young-Taek
authors.initials: YT
authors.lastname: Oh
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Heo
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008175:Lung Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Non-small cell lung cancer; Postoperative radiotherapy; Prognostic factor; Pulmonary function