Conclusion
NPM1 overexpression correlated with 18F-FDG PET/CT metabolic parameters and improved diagnostic accuracy in lung adenocarcinoma. SUVmax on 18F-FDG PET/CT may estimate NPM1 expression for targeted therapy of lung adenocarcinoma.
Methods
Forty-six lung adenocarcinoma patients who underwent 18F-FDG PET/CT before pulmonary surgery were retrospectively analysed. Metabolic parameters including SUVmax, SUVmean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated from 18F-FDG PET imaging data. The expression levels of NPM1 and TTF1 were assessed using The Cancer Genome Atlas (TCGA) database and immunohistochemistry of tumour tissues and adjacent normal lung tissues. We examined the association between the frequency of NPM1 and TTF1 expression and the metabolic parameters.
Purpose
This study investigated the correlation of nucleophosmin 1 (NPM1) expression with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computerised tomography scan (PET/CT)-related parameters and compared the diagnostic value of NPM1 with that of the positive biomarker TTF1 in lung adenocarcinoma patients.
Results
Lung adenocarcinoma samples expressed higher levels of NPM1 than adjacent normal lung epithelial tissues. NPM1 showed higher specificity and sensitivity for lung adenocarcinoma compared with TTF1 (p < 0.001). SUVmax, SUVmean and TLG correlated with NPM1 expression (p < 0.001). MTV was inversely correlated with TTF1 (p < 0.01). SUVmax was the primary predictor of NPM1 expression by lung adenocarcinoma (p < 0.01). A cutoff value for the SUVmax of 3.93 allowed 90.9% sensitivity and 84.6% specificity for predicting NPM1 overexpression in lung adenocarcinoma.