| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2141103 | Lung Cancer | 2013 | 8 Pages |
PurposeThe aim of this study was to evaluate the relationship and difference in prognostic significance between whole-body tumor burden, thoracic tumor burden, and extra-thoracic tumor burden on 18F-FDG PET/CT for patients with extensive-disease small cell lung cancer (ED-SCLC).Materials and methodsWe performed a retrospective, two-center analysis for patients with ED-SCLC who underwent pretreatment 18F-FDG PET/CT. Metabolic tumor burden was estimated using whole-body metabolic tumor volume (MTVWB), thoracic metabolic tumor volume (MTVTRX), extra-thoracic metabolic tumor volume (MTVEXT), and the number of extra-thoracic tumor foci. Uni- and multivariate analyses were performed using various clinical factors and the metabolic indices.ResultsA total of 91 patients were eligible for this study. MTVWB showed stronger correlation with MTVEXT than MTVTRX (r2 = 0.804 vs. 0.132, p < 0.001, both), whereas no correlation was observed between MTVEXT and MTVTRX (r2 = 0.007, p = 0.428). Patients with smaller MTVWB, MTVEXT, and extra-thoracic tumor foci showed longer survival than patients with larger MTVWB, MTVEXT, and extra-thoracic tumor foci, respectively, whereas the survival difference between patients with smaller MTVTRX and those with larger MTVTRX was not significant. Results of uni- and multivariate analyses showed that ECOG performance status (HR = 2.31, p = 0.015), initial chemotherapy cycles (HR = 0.24, p < 0.001), and the number of extra-thoracic tumor foci (HR = 2.75, p < 0.001) were independent prognostic factors for overall survival, and initial chemotherapy cycles (HR = 0.25, p < 0.001), and MTVEXT (HR = 2.04, p = 0.013) were independent prognostic factors for progression-free survival.ConclusionThese data provide evidence indicating that extra-thoracic tumor burden but not thoracic tumor burden is an independent prognostic biomarker for ED-SCLC, and support further exploration of novel treatment strategies targeting extra-thoracic tumor burden in order to improve the clinical outcomes of patients with ED-SCLC.
