Prognostic Impact of Histologic Grade and GLUT1 Expression in Patients with Lung Adenocarcinoma

Lung adenocarcinoma, a subtype of non-small cell lung cancer, exhibits heterogeneous biological characteristics depending on its histological subtype, which has clinically significant implications for the prognosis. This study examined the prognostic value of a classification system that combines the histological grade and GLUT1 expression level by analyzing the clinicopathological features and survival differences among subgroups of patients with lung adenocarcinoma. Two hundred and eight surgically resected patients were analyzed retrospectively and classified into four groups based on the histological grade (Grade 2 or 3) and GLUT1 expression level (Low or High). The clinicopathological parameters and survival outcomes were assessed using cross-tabulation, Kaplan-Meier survival analysis, and the Cox proportional hazards model. The histological grade and GLUT1 expression level were found to be independent prognostic factors, and the combined classification system showed a statistically significant difference in the disease-free survival among the groups (P<0.001). In particular, the Grade 3-High group had an approximately 2.7-fold increased risk of recurrence compared to the Grade 2-Low group (hazard ratio=2.672, P=0.040). This study highlights the clinical value of a simple and reproducible model that integrates the histological classification and a metabolic biomarker, providing an effective tool for evaluating the recurrence risk in patients with lung adenocarcinoma.