Prognostic value of the maximum standardized uptake value of pre-treatment primary lesions in small-cell lung cancer on 18F-FDG PET/CT: a meta-analysis

Background: 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has been widely used in clinical practice. However, the prognostic value of the pre-treatment standardized uptake value (SUV) for patients with small-cell lung cancer (SCLC) remains controversial. Purpose: To investigate the prognostic role of pre-treatment 18F-FDG PET on SCLC patients by meta-analysis. Material and Methods: Extensive literature searches of the PubMed, EMBASE, Web of Science, and Cochrane Library databases were conducted to identify literature published until 5 May 2017. Comparative analyses of the pooled hazard ratios (HRs) for event-free survival (EFS) and overall survival (OS) were performed to assess their correlations with the pre-treatment maximum SUV (SUVmax). Either the fixed- or the random-effects model was adopted, depending on the heterogeneity observed across the studies. Subgroup analyses were performed to assess the robustness of the results. Results: Twelve studies with 1062 patients were included. The pooled HR for OS of 11 studies was 1.13 (95% confidence interval [CI]=1.05-1.22; P=0.001; I-2=0%) and the pooled HR for EFS of nine studies was 1.09 (95% CI=1.02-1.17; P=0.014; I-2=0%), indicating that patients with high SUVs may have poorer prognoses. Begg's test detected no significant publication bias. The prognostic role of the SUVmax remained similar in the subgroup analyses. Conclusion: Our meta-analysis indicated that the pre-treatment SUVmax of primary lesions can be an important prognostic factor for OS and EFS in patients with SCLC. A high SUVmax may indicate poorer prognosis.