Prognostic value of early response assessment using (18F)FDG-PET in patients with advanced non-small cell lung cancer treated with tyrosine-kinase inhibitors

The purpose of this meta-analysis was to determine the prognostic value of early response assessment using (18F)fluorodeoxyglucose (FDG)-positron emission thermography (PET) in patients with advanced non-small cell lung cancer (NSCLC) treated with tyrosine-kinase inhibitors (TKIs). MEDLINE, PubMed, Cochrane, EMBASE, and Google Scholar databases were searched until August 1, 2016 using the keywords non-small cell lung carcinoma, positron-emission tomography, fluorodeoxyglucose, prognosis, disease progression, survival, erlotinib, gefitinib, and afatinib. Inclusion criteria were studies of patients with stage III or IV NSCLC treated with a TKI and had response assessed by FDG-PET. Outcome measures were overall survival (OS) and progression-free survival (PFS). Of the 167 articles identified, 10 studies including 302 patients were included in the analysis. In 8 studies, patients were treated with erlotinib, and in 2 they were treated with gefitinib. The overall analysis revealed that early metabolic response was statistically associated with improved OS (HR=0.54; 95% CI 0.46 to 0.63; p<0.001), and with longer PFS (HR=0.23; 95% CI 0.17 to 0.33; p<0.001). Early response of patients with NSCLC treated with TKIs identified on FDG-PET is associated with improved OS and PFS.