Prognostic value of FDG-PET scans at diagnosis in small cell lung cancer

Background: Small cell lung carcinoma (SCLC) is one of the most aggressive solid tumors. The predictive and prognostic role of positron emission tomography (PET) scans in SCLC is under investigation and is yet to be determined. Method: We retrospectively analyzed the correlation between overall survival and 2-[18F]-fluoro-2-deoxy-d-glucose- PET (FDG-PET) results at diagnosis. We also introduced the concept of the total standardized uptake value (SUV) as a possible biomarker for the total burden disease. In addition, we proposed a new staging concept using PET scan based on whether tumor uptake is or is not limited to parenchymal hemithorax. Results: Between March 2004 and February 2009, 46 patients with histologically confirmed SCLC were included in the analysis. Thirty patients were found to have Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 2, and most (65%, n = 30) of them had limited stage disease using conventional clinical staging criteria. There was a fair correlation between PET results and conventional staging by CT scan (kappa = 0.330). Although there was a trend toward upstaging by PET, it was not predictive of survival. There was a direct correlation between total SUV and maximum SUV and overall survival (hazard ratio [HR] = 1.003 and 1.085, respectively). Conclusion: PET scan results at diagnosis could play an important role in the management of SCLC. Total SUV could represent a good biomarker for the disease burden in SCLC. Further prospective studies are needed to clarify the application of total SUV in SCLC.