The predictive value of F-18-FDG PET/CT in an EGFR-mutated lung adenocarcinoma population

Background: A non-invasive, simple, and convenient method to evaluate the presence of epidermal growth factor receptor (EGFR) mutations is important for initial treatment decisions in lung adenocarcinoma. Methods: We retrospectively reviewed 297 untreated primary lung adenocarcinoma patients with exact EGFR status. Based on their EGFR status, the patients were divided into a mutant-type group (138 patients) and wild-type group (159 patients). General patient characteristics and possible factors reflecting the status of EGFR were also evaluated. Results: Of the 297 lung adenocarcinoma patients analyzed for EGFR status who underwent positron emission tomography (PET)/computed tomography ( CT) between January 2013 and December 2017, mutations in the EGFR gene were detected in 138 patients (46.5%). EGFR mutations were more frequently associated with women, never smokers, and low 18F-fluoro-2-deoxy-glucose (F-18-FDG) PET/CT maximal standard uptake value of the primary tumor (pSUVmax). Multivariate analysis indicated that women [odds ratio (OR) =2.853; 95% confidence interval (CI): 1.451-5.611; P=0.002], never smokers (OR =2.414; 95% CI: 1.217-4.789; P=0.012), tumor size <3.5 cm (OR, 2.170; 95% CI: 1.205-3.908; P=0.010), and pSUVmax <8.2 (OR =1.904; 95% CI: 1.098-3.302; P=0.022) were effective predictors of EGFR mutation. In addition, the area under the curve (AUC) of pSUVmax and tumor size was 0.623 and 0.600, respectively. Combined with clinical characteristics, including sex and smoking status, the AUC of the 4 predictors was 0.770. Conclusions: These indicators could be helpful for enhancing predictive accuracy of EGFR mutations in lung adenocarcinoma patients, especially in those for whom EGFR detection is unavailable.