Purpose: Primary central nervous system lymphoma (PCNSL) is a type of non-Hodgkin lymphoma (NHL), and it has been postulated that metabolic disorder may contribute to NHL etiology. We retrospectively investigated the prognostic significance of hyperglycemia in patients with PCNSL. We evaluated glucose transporter type 1 (GLUT1) expression by immunohistochemistry and analyzed its association with hyperglycemia and survival.
Methods: The medical and neuroradiologic records of 50 patients with PCNSL at our institution over the past 15 years were analyzed. Patients were divided into 3 groups based on mean fasting plasma glucose (FPG) levels: normal (<110 mg/dL), prediabetes (110-125 mg/dL), and diabetes (≥126 mg/dL). We defined prediabetes and diabetes groups as hyperglycemia.
Results: Forty-four percent of patients were in the prediabetes and diabetes groups. One-year survival rates were 73%, 66%, and 43% in normal, prediabetes, and diabetes groups, respectively. Univariate analysis revealed that high age, female sex, poor performance status, high mean FPG, and monotherapy were associated with shorter survival. Multivariable Cox regression analyses showed that high mean FPG and monotherapy were significant predictors of shorter survival (p = 0.036 and p = 0.000, respectively). The GLUT1 immunohistopathologic staining was performed in 34 cases, 20 of which (58%) showed variable levels of GLUT1 expression at the cell membrane and/or cytoplasm. Prediabetes and diabetes groups had a higher percentage of GLUT1-positive cells compared with the normal group (p = 0.015).
Conclusions: These findings indicate that hyperglycemia is associated with poor survival. The putative biological mechanism might involve differential GLUT1 expression between hyperglycemic and normal states in patients with PCNSL.