Difference in Prognostic Significance of Maximum Standardized Uptake Value on [18F]-Fluoro-2-Deoxyglucose Positron Emission Tomography Between Adenocarcinoma and Squamous Cell Carcinoma of the Lung

Objective: This study evaluates the prognostic significance of [18F]-fluoro-2-deoxyglucose positron emission tomography/computed tomography findings according to histological subtypes in patients with completely resected non-small cell lung cancer. Methods: We examined 176 consecutive patients who had undergone preoperative [18F]-fluoro-2-deoxyglucose-positron emission tomography/computed tomography imaging and curative surgical resection for adenocarcinoma (n = 132) or squamous cell carcinoma (n 44). Maximum standardized uptake values for the primary lesions in all patients were calculated as the [18F]-fluoro-2-deoxyglucose uptake and the surgical results were analyzed. Results: The median values of maximum standardized uptake value for the primary tumors were 2.60 in patients with adenocarcinoma and 6.95 in patients with squamous cell carcinoma (P < 0.001). Analyses of receiver operating characteristic curves identified an optimal maximum standardized uptake value cutoff value to predict recurrence of 3.7 for adenocarcinoma, whereas such an indicator could not be identified for squamous cell carcinoma. Although 2-year disease-free survival rates were 70.2% for maximum standardized uptake value <= 6.95 and 59.3% for maximum standardized uptake value >6.95 (P = 0.83) among patients with squamous cell carcinoma, 2-year disease-free survival rates were 93.9% for maximum standardized uptake value <= 3.7 and 52.4% for maximum standardized uptake value >3.7 (P, < 0.0001) among those with adenocarcinoma, and notably, 100 and 57.2%, respectively, in patients with Stage I adenocarcinoma (P < 0.0001). On the basis of the multivariate Cox analyses of patients with adenocarcinoma, maximum standardized uptake value (P = 0.008) was a significantly independent factor for disease-free survival as well as nodal metastasis (P = 0.001). Conclusions: Maximum standardized uptake value of the primary tumor was a powerful prognostic determinant for patients with adenocarcinoma, but not with squamous cell carcinoma of the lung.