title: Prognostic factors affecting the risk of thoracic progression in extensive-stage small cell lung cancer.
abstract: BACKGROUND
  The efficacy of combined modality therapy is evaluated for patients with extensive-stage (ES) small cell lung cancer (SCLC). This study evaluated prognostic factors affecting the risk of thoracic progression in ES-SCLC patients likely to undergo thoracic radiotherapy combined chemotherapy.
  
  
  METHODS
  A retrospective review of ES-SCLC patients who had received systemic chemotherapy at our hospital was performed. Tumor size, metastatic sites, and laboratory data at diagnosis were evaluated as potential prognostic factors. In ES-SCLC patients without pleural dissemination, the rate of thoracic progression after initial chemotherapy was assessed.
  
  
  RESULTS
  Eighty-three of 96 consecutive ES-SCLC patients were analyzed. The overall response rate was 55 %, median progression free survival was 5.0 months (mo), and overall survival (OS) was 9.2 mo. Tumor size (19.4 mo for ≤3 cm vs. 8.5 mo for >3 cm, p = 0.017) and the number of metastatic sites (12.9 mo for single sites vs. 7.1 mo for multiple sites, p = 0.015) were prognostic factors, in addition to known prognostic factors such as performance status and the levels of LDH and sodium. Cox proportional hazard model showed that the OS was significantly worse in patients with large (>3 cm) primary tumor size {HR 2.44 [95 % confidential interval (CI) 1.05-5.68], p = 0.038} and multiple metastatic sites [HR 1.81 (95 % CI 1.08-3.04), p = 0.026]. In 51 cases without pleural dissemination, the number of metastatic sites was associated with thoracic progression after initial chemotherapy (65 % for single sites vs. 36 % for multiple sites, p = 0.036).
  
  
  CONCLUSIONS
  Large tumor size and multiple metastatic sites at diagnosis significantly predicted poor survival in ES-SCLC patients. Based on the high rate of thoracic progression in ES-SCLC patients with single site of distant metastasis, we should consider thoracic radiotherapy combined with chemotherapy for this population.
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. tofukui@med.kitasato-u.ac.jp.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. m-kimura@kitasato-u.ac.jp.
authors.forename: Michiko
authors.initials: M
authors.lastname: Itabashi
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. stonefld@kitasato-u.ac.jp.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. hiyoshi@kitasato-u.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hiyoshi
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. kasajima@kitasato-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kasajima
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. igawa@kitasato-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Igawa
authors.affiliation: Research and Development Center for New Medical Frontiers, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. saji@med.kitasato-u.ac.jp.
authors.forename: Jiichiro
authors.initials: J
authors.lastname: Sasaki
authors.affiliation: Department of Respiratory Medicine, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan. masuda@med.kitasato-u.ac.jp.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Masuda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D018450:Disease Progression; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D055752:Small Cell Lung Carcinoma / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D013909:Thorax / Q000473:pathology*; D016896:Treatment Outcome; D047368:Tumor Burden