Prognostic Significance of 18F-FDG PET/CT Metabolic Parameters and Tumor Galectin-1 Expression in Patients With Surgically Resected Lung Adenocarcinoma

Galectin-1 (Gal-1) is a regulatory checkpoint that promotes immunosuppression and cancer development. We examined Gal-1 expression through immunohistochemistry and found that there was a significant positive correlation between Gal-1 expression and positron emission tomography/computed tomography (PET/CT) metabolic parameters in patients with surgically resected lung adenocarcinoma. Our results highlight PET/CT can predict Gal-1 expression and prognosis in lung adenocarcinoma. Purpose: To study the prognostic significance of F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET)/computed tomography (CT) metabolic parameters and tumor galectin-1 (Gal-1) expression in patients surgically treated for lung adenocarcinoma. Patients and Methods: The medical records of 96 patients with primary lung adenocarcinoma who underwent surgery after F-18-FDG PET/CT were retrospectively reviewed. The maximal standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis of the primary tumor were measured through PET/CT imaging. The expression of tumor Gal-1, glucose transporter 1 (GLUT-1), and hexokinase II (HK-II) were examined through immunohistochemistry. Results: There were significant positive correlations between tumor Gal-1 and SUVmax, tumor Gal-1 and metabolic tumor volume, tumor Gal-1 and total lesion glycolysis, tumor Gal-1 and GLUT-1 expression, tumor Gal-1 and HK-II expression, and SUVmax and tumor GLUT-1 and HK-II expression (P < .0001 in all cases). SUVmax was the only independent predictor of tumor Gal-1 expression. On receiver operating characteristic analysis, the optimal cutoff value of SUVmax for predicting tumor Gal-1 expression was 5.1. Progression-free and overall survival were significantly shorter in patients with Gal-1-positive tumors than in those with Gal-1-negative tumors (P <= .001). On multivariate analysis, advanced tumor stage (P = .001) and tumor Gal-1 expression (P < .0001) were independent prognostic indicators of poor progression-free survival, while advanced tumor stage (P < .0001) and SUVmax (P = .024) were independent prognostic indicators of poor overall survival. Conclusion: 18F-FDG PET/CT has the potential to be used as a noninvasive imaging modality to assess tumor Gal-1 status and prognosis in lung adenocarcinoma.