title: Development and external validation of prognostic model for 2-year survival of non-small-cell lung cancer patients treated with chemoradiotherapy.
abstract: OBJECTIVE
  Radiotherapy, combined with chemotherapy, is the treatment of choice for a large group of non-small-cell lung cancer (NSCLC) patients. Recent developments in the treatment of these patients have led to improved survival. However, the clinical TNM stage is highly inaccurate for the prediction of survival, and alternatives are lacking. The objective of this study was to develop and validate a prediction model for survival of NSCLC patients, treated with chemoradiotherapy.
  
  
  METHODS
  The clinical data from 377 consecutive inoperable NSCLC patients, Stage I-IIIB, treated radically with chemoradiotherapy were collected. A prognostic model for 2-year survival was developed, using 2-norm support vector machines. The performance of the model was expressed as the area under the curve of the receiver operating characteristic and assessed using leave-one-out cross-validation, as well as two external data sets.
  
  
  RESULTS
  The final multivariate model consisted of gender, World Health Organization performance status, forced expiratory volume in 1 s, number of positive lymph node stations, and gross tumor volume. The area under the curve, assessed by leave-one-out cross-validation, was 0.74, and application of the model to the external data sets yielded an area under the curve of 0.75 and 0.76. A high- and low-risk group could be clearly identified using a risk score based on the model.
  
  
  CONCLUSIONS
  The multivariate model performed very well and was able to accurately predict the 2-year survival of NSCLC patients treated with chemoradiotherapy. The model could support clinicians in the treatment decision-making process.
authors.affiliation: Department of Radiotherapy, MAASTRO Clinic, Research Institute of Growth and Development, University Hospital Maastricht, University Maastricht, The Netherlands. cary.dehing@maastro.nl
authors.forename: Cary
authors.initials: C
authors.lastname: Dehing-Oberije
authors.forename: Shipeng
authors.initials: S
authors.lastname: Yu
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ruysscher
authors.forename: Sabine
authors.initials: S
authors.lastname: Meersschout
authors.forename: Karen
authors.initials: K
authors.lastname: Van Beek
authors.forename: Yolande
authors.initials: Y
authors.lastname: Lievens
authors.forename: Jan
authors.initials: J
authors.lastname: Van Meerbeeck
authors.forename: Wilfried
authors.initials: W
authors.lastname: De Neve
authors.forename: Bharat
authors.initials: B
authors.lastname: Rao
authors.forename: Hiska
authors.initials: H
authors.lastname: van der Weide
authors.forename: Philippe
authors.initials: P
authors.lastname: Lambin
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy; D015331:Cohort Studies; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D005541:Forced Expiratory Volume; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy; D008207:Lymphatic Metastasis; D008297:Male; D015233:Models, Statistical; D049451:Nomograms; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D012720:Severity of Illness Index; D012737:Sex Factors; D016019:Survival Analysis; D015996:Survival Rate; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18