Associations Between FDG PET and Expression of VEGF and Microvessel Density in Different Solid Tumors: A Meta-analysis

Background: To date, there are inconsistent data about relationships between 2-deoxy-2 [F-18] fluoro-D-glucose positron emission tomography (FDG-PET) and expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD). The aim of the present meta-analysis was to systematize the reported data about associations between maximal standardized uptake value (SUVmax) derived from FDG PET and expression of VEGF and as well as MVD. Methods: MEDLINE library, SCOPUS and EMBASE data bases were screened for relationships between SUVmax and VEGF/MVD up to October 2019. Overall, in 18 studies correlations between SUVmax and VEGF and in 13 studies correlations between SUVmax and MVD were reported. The following data were extracted from the literature: authors, year of publication, number of patients, and correlation coefficients. Results: Associations between 18F-FDG PET and VEGF were reported in 18 studies (935 patients). The calculated correlation coefficients between SUVmax and VEGF expression ranged from -0.16 to 0.88. The pooled correlation coefficient was 0.32, (95% confidence interval [CI] = [0.15; 0.48]). Associations between 18F-FDG PET and MVD were investigated in 13 studies (593 patients). The reported correlation coefficients ranged from -0.23 to 0.91. The pooled correlation coefficient was 0.27, (95% CI = [0.00; 0.53]). Analysis of MVD based on CD105 immunohistochemical staining was performed in four studies (117 patients). The pooled correlation coefficient was 0.41 (95% CI = [0.22; 0.59]). In three reports with 233 patients, MVD was estimated by staining with CD31 antibody. The pooled correlation coefficient was 0.01, (95% CI = [-0.44; 0.47]). Finally, in 9 studies (280 patients) MVD was performed on CD34 stained specimens. The pooled correlation coefficient was 0.36, (95% CI = [0.09; 0.63]). Conclusion: SUVmax of FDG PET correlated weakly with expression of VEGF and with MVD. Therefore, FDG PET cannot predict neoangiogenesis in malignant tumors.

Automated summary

This meta-analysis systematically reviewed the associations between SUVmax from FDG PET and the expression of VEGF and MVD. The results indicated a weak correlation between SUVmax and VEGF/MVD, suggesting that FDG PET may not be able to predict neoangiogenesis in malignant tumors.