The difference in relationship between 18F-FDG uptake and clinicopathological factors on thyroid, esophageal, and lung cancers

ObjectivesThe aim of this study was to reveal the differences in clinicopathological factors affecting maximum standardized uptake value (SUVmax) between esophageal squamous cell carcinoma (ESCC), non-small-cell lung cancer (NSCLC), and papillary thyroid cancer (PTC).MethodsThis study consisted of 119 patients with ESCC (n=43), PTC (n=40), or NSCLC (n=36). We investigated the correlations between SUVmax and clinicopathological factors by using Spearman's correlation coefficient and the Kruskal-Wallis test. Multiple regression analysis was used to investigate which clinicopathological factors significantly affected SUVmax in each cancer type.ResultsThe SUVmax correlated with glucose transporter-1 (GLUT-1) expression in NSCLC (r=0.536, P=0.007) and ESCC (r=0.597, P<0.001) but not in PTC. The SUVmax correlated with Ki-67 expression in NSCLC (r=0.381, P=0.022) and PTC (r=0.374, P=0.017) but not in ESCC. A high SUVmax was correlated with a higher pathological T stage (p-T stage) in NSCLC (r=0.536) and ESCC (r=0.597, both P<0.001) but not in PTC. An elevated SUVmax was significantly associated with pathological lymph node status (p-N) in NSCLC, but not in ESCC and PTC. In multiple regression analysis, p-T stage and GLUT-1 expression were statistically significant factors in ESCC, and p-T stage was a statistically significant factor in NSCLC. In PTC, Ki-67 showed a statistically significant association with SUVmax.ConclusionSUV(max) in NSCLC depended on the tumor invasion area; SUVmax in ESCC depended on tumor depth and GLUT-1 expression; and SUVmax in PTC might be associated with cell proliferation. The biological factors affecting SUVmax differ according to tumor type.