title: Benefit from thoracic radiotherapy in patients with extensive-disease small-cell lung cancer with elevated lactate dehydrogenase.
abstract: BACKGROUND
  High lactate dehydrogenase (LDH) is associated with a large tumor burden in extensive-disease small-cell lung cancer (ED-SCLC). This study evaluated the benefit of additional thoracic radiotherapy (TRT) in patients with ED-SCLC with elevated LDH.
  
  
  METHODS
  We analyzed 94 patients with ED-SCLC and evaluated LDH at Sun Yat-sen University Cancer Center during the period between January 2000 and March 2010. Patients were divided into two groups according to whether TRT was received. Survival was evaluated by the Kaplan-Meier method and Cox's regression analysis.
  
  
  RESULTS
  The median age of the 94 patients with ED-SCLC was 58.5 years. The main metastatic sites included the liver, bone, brain, and adrenal glands. The response rate in the TRT group was 46.9%. There were 32 patients (34.04%) receiving TRT and 5.3% receiving prophylactic cranial irradiation. The median survival time reached 10 months (95% confidence interval: 8.22, 11.78 months), and the 1-, 2-, and 5-year survival rates were 43.6%, 11.7%, and 2.1%, respectively. There was a significant difference in the median progression-free survival (PFS) and overall survival (OS) between the TRT group and the no TRT group (PFS: 9.0 months vs 6.0 months, P=0.018; OS: 13.0 months vs 9.0 months, P=0.006).
  
  
  CONCLUSIONS
  The use of TRT improves the survival of patients with ED-SCLC. Future studies should use the LDH level for categorizing patients for treatment.
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, The State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Qin
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, The State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Breast Tumor Center, Sun Yat-sen University Sun Yat-sen Memorial Hospital, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Yin-Duo
authors.initials: YD
authors.lastname: Zeng
authors.affiliation: Breast Tumor Center, Sun Yat-sen University Sun Yat-sen Memorial Hospital, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Dinglin
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, The State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Radiotherapy, Hunan Cancer Hospital, Central South University, Key Laboratory of Translational Radiation Oncology, Changsha, Hunan, People's Republic of China; Department of Radiotherapy, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Key Laboratory of Translational Radiation Oncology, Changsha, Hunan, People's Republic of China.
authors.forename: Huai
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Medical Oncology, Sun Yat-sen University Cancer Center, The State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Likun
authors.initials: L
authors.lastname: Chen
keywords: LDH; extensive stage; small-cell lung cancer; thoracic radiotherapy