When stratified by tumor histology, the association between the GLUT3 rs7309332C>T and OS/DFS was not limited to either squamous cell carcinoma (SCC) or adenocarcinoma (AC), although the significant association remained only in AC for OS (P = 0.40 for SCC and P = 0.04 for OS) and only in SCC for DFS (P = 0.03 for SCC and P = 0.08 for OS).
In addition, localized AC in situ revealed a considerably higher positive expression rate and similar degrees of overexpression for both Glut-1 and Glut-3 compared with AC-mixed.
The present study supports the hypothesis that tumor cell differentiation in combination with overexpression of GLUT-1 and GLUT-3 determine the extent of FDG accumulation and that squamous cell carcinomas accumulate more FDG than adenocarcinomas or large cell carcinomas.