title: High tumor metabolic activity as measured by fluorodeoxyglucose positron emission tomography is associated with poor prognosis in limited and extensive stage small-cell lung cancer.
abstract: OBJECTIVE
  We investigated the prognostic effect of incorporating metabolic assessment by (18)F-fluoro-2-deoxyglucose uptake on positron emission tomography/computed tomography ((18)F-FDG-PET/CT) into a conventional staging system in small-cell lung cancer (SCLC).
  
  
  METHODS
  Seventy-six consecutive patients with pathologically proven SCLC were enrolled. All patients underwent standard treatment after pretreatment (18)F-FDG-PET/CT scanning. The mean values of maximal standardized uptake values (meanSUV(max)) of the malignant lesions upon (18)F-FDG-PET/CT were calculated. The Cox proportional hazards model was used with performance status, lactate dehydrogenase, stage, and meanSUV(max).
  
  
  RESULTS
  Patients with high meanSUV(max) were significantly related with the established poor prognostic factors, such as higher lactate dehydrogenase (P = 0.04) and extensive disease (ED; P = 0.01). Furthermore, in multivariate analysis, patients with high meanSUV(max) were associated with poor survival outcomes compared with patients with low meanSUV(max) [adjusted hazard ratio, 3.74; 95% confidence interval (95% CI), 1.67-8.37; P = 0.001, for death and adjusted hazard ratio, 2.25; 95% CI, 1.21-4.17; P = 0.01 for recurrence/progression]. In subgroup analysis, limited disease (LD) with high meanSUV(max) showed significantly shorter overall survival than LD with low meanSUV(max) [high versus low meanSUV(max), 20.1 months (95% CI, 7.9-23.2) versus 35.3 months (95% CI, 27.6-42.9); P = 0.02]. ED with high meanSUV(max) had significantly shorter overall survival than ED with low meanSUV(max) [high versus low meanSUV(max), 9.5 months (95% CI, 4.9-13.9) versus 17.7 months (95% CI, 12.0-20.1); P = 0.007]. These findings were replicated in progression-free survival analysis.
  
  
  CONCLUSIONS
  In SCLC, tumor metabolic activity as assessed by FDG-PET is a significant prognostic factor and identifies subgroups of patients at higher risk of death in both LD and ED SCLC.
authors.affiliation: Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Lee
authors.forename: Arthur
authors.initials: A
authors.lastname: Cho
authors.forename: Byoung Chul
authors.initials: BC
authors.lastname: Cho
authors.forename: Mijin
authors.initials: M
authors.lastname: Yun
authors.forename: Se Kyu
authors.initials: SK
authors.lastname: Kim
authors.forename: Joon
authors.initials: J
authors.lastname: Chang
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Moon
authors.forename: In Kyu
authors.initials: IK
authors.lastname: Park
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Choi
authors.forename: Joo-Hang
authors.initials: JH
authors.lastname: Kim