Metabolic Characteristics of Surgically Resectable Lung Adenocarcinoma according to Mutational Profile

초록

Objectives: Metabolic Characteristics of Surgically Resectable Lung Adenocarcinoma according to Mutational Profile Propose: We aimed to investigate the metabolic characteristics of epidermal growth factor receptor (EGFR)-mutated and anaplastic lymphoma kinase (ALK)-rearranged lung adenocarcinoma by 18F-FDG PET/CT. Methods: We retrospectively included a total of 53 patients with initially diagnosed lung adenocarcinoma after curative surgery between January 2010 and December 2015. The primary tumors were classified as EGFR (+), ALK (+) and wild type (WT) according to mutational status. We measured SUVmax, metabolic tumor volume with cutoff value of 50% SUVmax (MTV50) and total lesion glycolysis (TLG) of primary lung tumor lesion on 18F-FDG PET/CT and then compared metabolic parameters with histopathologic findings. Results: Of the 53 patients (M:F = 28:25), the mean age was 65.6 ± 8.9 yrs. Among them, 22 (41.5 %), 10 (18.9 %) and 21 (39.6 %) were in EGFR (+) group, ALK (+) group and WT, respectively. The tumor size was not significantly different between groups (P = 0.248). The SUVmax was not correlated with tumor size in EGFR (+) group (P = 0.928), whereas ALK (+) group and WT showed significant correlation between tumor size and SUVmax (Pearson’s coefficient of 0.796 and 0.455, P value of 0.006 and 0.038, respectively). The EGFR (+) group tended to show lower TLG value (18.6 ± 9.1) than ALK (+) group (33.6 ± 41.6) and WT (60.1 ± 82.1) (P = 0.055), whereas SUVmax and MTV50 showed no significant difference between groups (P = 0.173 and 0.270, respectively). Conclusions: EGFR-mutated lung adenocarcinoma represents low glucose metabolism regardless of tumor size, which implies more careful 18F-FDG PET/CT interpretation is necessary in patients with resectable disease.