Abstract
OBJECTIVE: To explore the valuable predictors for evaluating progression-free survival (PFS) in patients with lung adenocarcinoma, we analyzed the potential roles of standardized uptake value (SUV)-derived parameters from (18)F-FDG PET/CT, combining with the gene mutation states of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and other clinical characteristics. METHODS: Data of 84 lung adenocarcinoma patients pre-treated, who underwent (18)F-FDG PET/CT scans, EGFR gene mutations test, ALK rearrangement assay and other relative tests, were retrospectively collected. Then a series of clinical parameters including EGFR/ALK mutation status and SUV-derived features [maximum standardized uptake value (SUVmax), average of standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)] were evaluated. Best possible cutoff points for all measuring parameters were calculated using receiver operating characteristic curve (ROC) analysis. Survival analysis was performed using Cox proportional hazards model to determine the prognostic markers for progression-free survival (PFS). Survival curves were obtained through Log-rank test and Kaplan-Meier curve. RESULTS: The median follow-up period was 31 months (24 to 58 months). It was found that SUVmax (≥3.01), SUVmean (≥2.25), MTV (≥25.41 cm(3)), and TLG (≥55.02) of the primary tumors were significantly associated with PFS in univariate Cox proportional hazards regression. Then regardless of age, gender, co-morbidity, EGFR/ALK mutation status, and treatment program, TLG (≥ 55.02, HR=4.965, 95%CI: 1.360-18.133), TNM stage (Ⅲ/Ⅳ, HR=7.811, 95%CI: 2.977-20.489), pro-gastrin releasing peptide (proGRP) (≥45.65 ng/L, HR=4.070, 95%CI: 1.442-11.487), tissue polypeptide antigen (TPA) (≥68.20 U/L, HR=6.996, 95%CI: 1.458-33.574), alkaline phosphatase (ALP) (≥82.50 IU/L, HR=4.160, 95%CI: 1.416-12.219) and ratio of activated partial thromboplastin time (aPTTR) (≥1.16: HR=4.58, 95%CI: 1.913-10.946) showed the independently relevant to PFS through multivariate Cox proportional hazards analysis. The EGFR mutant (P=0.343) and ALK rearrangement (P=0.608) were not significant either in survival analysis. CONCLUSION: High SUV-derived parameters (SUVmax, SUVmean, MTV and TLG) might provide prognostic value to some extent. Especially, TLG, and other clinical features [TNM stage, proGRP, TPA, ALP, and aPTTR] could be independently and significantly associated with PFS of lung adenocarcinoma patients. However, EGFR/ALK gene status could not be effectively relevant to PFS in lung adenocarcinoma patients.