Prognostic Value of Baseline (18)F-FDG PET/CT Functional Parameters in Patients with Advanced Lung Adenocarcinoma Stratified by EGFR Mutation Status

The study objective was to retrospectively analyze the metabolic variables derived from 18 F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) as predictors of progression-free survival (PFS) and overall survival (OS) in advanced lung adenocarcinoma stratified by epidermal growth factor receptor (EGFR) mutation status. A total of 176 patients (91, EGFR mutation; 85, wild-type EGFR) who underwent (18)F-FDG PET/CT before treatment were enrolled. The main (18)F-FDG PET/CT-derived variables: primary tumor maximum standardized uptake value (SUV(maxT)), primary tumor total lesion glycolysis (TLG(T)), the maximum SUV(max) of all selected lesions in whole body determined using the Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria (SUV(maxWBR)), and whole-body total TLG determined using the RECIST 1.1 criteria (TLG(WBR)) were measured. Survival analysis regarding TLG(WBR,) and other factors in advanced lung adenocarcinoma patients stratified using EGFR mutation status, were evaluated. The results indicated that high TLG(WBR) (≥259.85), EGFR wild-type, and high serum LDH were independent predictors of worse PFS and OS in all patients with advanced lung adenocarcinoma. Among patients with wild-type EGFR, only TLG(WBR) retained significance as an independent predictor of both PFS and OS. Among patients with the EGFR mutation, high serum LDH level was an independent predictor of worse PFS and OS, and high TLG(WBR) (≥259.85) was an independent predictor of worse PFS but not worse OS. In conclusion, TLG(WBR) is a promising parameter for prognostic stratification of patients with advanced lung adenocarcinoma and EGFR status; however, it cannot be used to further stratify the risk of worse OS for patients with the EGFR mutation. Further prospective studies are needed to validate our findings.