title: Stereotactic Body Radiation Therapy and the Influence of Chemotherapy on Overall Survival for Large (≥5 Centimeter) Non-Small Cell Lung Cancer.
abstract: Stereotactic body radiation therapy (SBRT) for ≥5 cm lesions is poorly defined, largely owing to the low sample sizes in existing studies. The present analysis examined the SBRT outcomes and assessed the effect of chemotherapy in this population.
  
  
  
  The National Cancer Data Base was queried for primary non-small cell lung cancer ≥5 cm treated with SBRT (≤10 fractions). Patient, tumor, and treatment parameters were extracted. The primary outcome was overall survival (OS). Statistical methods involved Kaplan-Meier analysis and multivariable Cox proportional hazards modeling.
  
  
  
  From 2004 to 2012, data from 201 patients were analyzed. The median follow-up was 41.1 months. The median tumor size was 5.5 cm (interquartile range 5.0-6.0), with cT2a, cT2b, and cT3 disease in 24.9%, 53.2%, and 21.9%, respectively. The median total SBRT dose and fractionation was 50 Gy in 4 fractions, and 92.5% of the patients underwent SBRT with ≤5 fractions. The median OS was 25.1 months. Of the 201 patients, 15% received chemotherapy. The receipt of chemotherapy was associated with longer OS (median 30.6 vs 23.4 months; P=.027). On multivariable analysis, worse OS was seen with increasing age (hazard ratio [HR] 1.03; P=.012), poorly differentiated tumors (HR 2.06; P=.049), and T3 classification (HR 2.13; P=.005). On multivariable analysis, chemotherapy remained independently associated with improved OS (HR 0.57; P=.039).
  
  
  
  SBRT has utility in the setting of tumors ≥5 cm, with chemotherapy associated with improved OS in this subset. These hypothesis-generating data now raise the necessity of performing prospective analyses to determine whether chemotherapy confers outcome benefits after SBRT.
authors.affiliation: Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Vivek
authors.initials: V
authors.lastname: Verma
authors.affiliation: Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: McMillan
authors.affiliation: Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Surbhi
authors.initials: S
authors.lastname: Grover
authors.affiliation: Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: charles.simone@uphs.upenn.edu.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Simone
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D016208:Databases, Factual; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D016016:Proportional Hazards Models; D016634:Radiosurgery / Q000401:mortality; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents