Fluorodeoxyglucose positron emission tomography and tumor marker expression in non-small cell lung cancer

The best current noninvasive surrogate for tumor biology is fluorodeoxyglucose positron emission tomography (FDG-PET). Both FDG-PET maximal standardized uptake values and selected tumor markers have been shown to correlate with stage, nodal disease, and survival in non-small cell lung cancer (NSCLC). However, there are limited data correlating FDG-PET with tumor markers. The purpose of this study was to determine the correlation of tumor marker expression with FDG-PET maximal standardized uptake values in NSCLC.

FDG-PET maximal standardized uptake values were calculated in patients with NSCLC (n = 149). No patient had induction chemoradiotherapy. Intraoperative NSCLC tissue was obtained and tissue microarrays were created. Immunohistochemical analysis was performed for 5 known NSCLC tumor markers (glucose transporter 1, p53, cyclin D1, epidermal growth factor receptor, and vascular endothelial growth factor). Each tumor marker was assessed independently by two pathologists using common grading criteria. Subgroup analysis based on histologic characteristics and regional nodal status was performed.

FDG-PET correlated with T classification (P < .0001), N stage (P = .002), and greatest tumor dimension (P < .0001). In addition, increasing maximal standardized uptake values correlated with increased expression of glucose transporter 1 (P < .0001) and p53 (P = .04) in adenocarcinoma. Epidermal growth factor receptor expression correlated with maximal standardized uptake values without predilection for histologic subtype (P = .004).

FDG-PET maximal standardized uptake values correlate with an increased expression of glucose transporter 1 and p53 in lung adenocarcinoma, but not squamous cell cancer. Future studies attempting to correlate FDG-PET with tumor biology will need to consider the effect of different tumor histologic types.