Metabolic Activity on [18F]-FluorodeoxyglucosePositron Emission Tomography/Computed Tomography and Glucose Transporter-1 Expression Might Predict Clinical Outcomes in Patients With Limited Disease Small-Cell Lung Cancer Who Receive Concurrent Chemoradiation

Forty-one patients with limited disease small-cell lung cancer (LD-SCLC) received etoposide (120 mg/m(2) intravenously [I. V.], days 1-3) and cisplatin(60mg/m(2) I. V., day 1) combination chemotherapywith concurrentmediastinal irradiation, and response was evaluated using chest and abdominal computed tomography (CT) scans and [18F]fluorodeoxyglucose- positron emission tomography (FDG-PET)/CT. Thirty-one tumor biopsy specimens were immunostained to determine glucose transporter-1 (GLUT-1), B-cell lymphoma 2 (Bcl-2), and hypoxia-inducible factor-1a (HIF-1a) expression. Metabolic responders evaluated using FDG-PET showed better relapse-free survival (RFS), and patients with a higher percentage of GLUT-1-positive tumor cells showed better tumor response. Background: Limited disease small-cell lung cancer responds well to concurrent chemoradiation therapy (CCRT), but shows high relapse rate and short RFS. We aimed to evaluate tumor metabolic activities measured using FDG-PET as a prognostic factor and analyze its relationships with markers of tumor biologic behavior. Patients and Methods: Fortyone LD-SCLC patients receiving 4 cycles of EP (etoposide 120 mg/m(2), days 1-3; cisplatin 60 mg/m(2), day 1), 2 cycles of EP (etoposide 130 mg/m(2), days 1-3; cisplatin 30 mg/m(2), day 1)-CCRT were enrolled. Maximum standardized uptake value (SUV; SUVmax) of primary tumor was revised with SUV of liver (SUVlivermax). Differences between pre-, posttreatment average SUV uptake of primary tumor, and intrathoracic lymph nodes were presented as DSUVliveravg. Thirtyone tumor biopsy specimens were immunostained for GLUT-1, Bcl-2, and HIF-1a. Results: The median overall survival (OS), and RFS were 13.7 and 10.4 months, respectively. In multivariate analysis, pretreatment lactate dehydrogenase (LDH) and DSUVliveravg correlated with RFS (hazard ratio [HR], 2.8, P = .043; HR, 0.3, P = .004). Sex, LDH, objective tumor metabolic response, and SUVlivermax correlated with OS (HR, 12.1, P = .006; HR, 3.7, P = .037; HR, 10.1, P = .008; and HR, 0.2, P = .014, respectively). High GLUT-1 positivity (> 75%), and LDH level (> 400 U/L) correlated with better objective response rate (P = .012) and HIF-1a immunoreactivity score (P = .029). Conclusion: DSUVliveravg and GLUT-1 expression might predict RFS and ORR in patients with LD-SCLC treated with definitive CCRT.