Glucose transporters and FDG uptake in untreated primary human non-small cell lung cancer

PET imaging of malignant tumors with 2-[fluorine-18]-fluoro-2-deoxy-D-gluco se (FDG) as a tracer is a noninvasive diagnostic and prognostic tool that m easures tumor metabolism. In this study, we assessed the relationships betw een FDG uptake and the expression of facilitative glucose transporters, the sizes of populations of proliferating cells and infiltrating macrophages i n patients with primary non-small cell lung cancers (NSCLC). Methods: FDG u ptake and the expression of five glucose transporters and the proportions o f proliferating cell and macrophage populations were studied in paraffin se ctions from untreated primary lung cancers by immunohistochemistry. The pat ients were imaged with FDG PET before surgery. Results: All tumors could be detected by FDG PET. Uptake was correlated with tumor size (P = 0.004). FD G uptake was lower in adenocarcinomas (ACs) than in squamous cell carcinoma s (SQCs) (P = 0.03) or large cell carcinomas (P = 0.002) [standardized upta ke value corrected for lean body mass (SUL) = 5.42 +/- 2.77, 8.04 +/- 3.25 and 10.42 +/- 4.54, respectively], Glut-1 expression was significantly high er than that of any other transporter. All tumors tested (n = 23) were Glut -1-positive (70.8% +/- 26.1% of tumor cell area was positive and staining i ntensity was 2.8 +/- 1.2). Glut-1 expression was higher in SQCs (78% +/- 17 .8% and 3.5 +/- 0.6) than in ACs (47.5% +/- 30.3% and 1.6 +/- 1.1; P = 0.04 4 for positive tumor cell area and P = 0.005 for staining intensity). Proli ferating cells constituted 15.3% +/- 13.1% of the cancer cells, and the ave rage number of macrophages was 7.8% +/- 6.3%; neither correlated with FDG u ptake. Conclusion: In this population of patients with NSCLC, Glut-1 is the major glucose transporter expressed. Both FDG uptake and Glut-1 expression appear to be associated with tumor size. No association was found between FDG uptake and either macrophage or proliferative cell populations.