The prognostic role of preoperative serum albumin levels in glioblastoma patients

Abstract

Background: Serum albumin level is a reliable and convenient marker of the nutritional status of patients, and has been identified as a prognostic marker in glioblastoma. However, because of the recent wide application of standard radio-chemotherapy for the treatment of glioblastoma patients, the prognostic effect of preoperative serum albumin levels needs to be re-evaluated and the related mechanism should be further explored.

Methods: A total of 214 patients with histologically proven glioblastoma who underwent treatment at our institution between 2009 and 2012 were retrospectively analyzed. Clinical information was obtained from electronic medical records. Kaplan-Meier analysis and Cox proportional hazards models were used to examine the survival function of preoperative serum albumin levels in these glioblastoma patients.

Results: Serum albumin levels were significantly correlated with overall survival in glioblastoma patients (multivariate HR = 0.966; 95% CI, 0.938-0.995; P = 0.023). Serum albumin level was high in patients receiving standard therapy, which may affect its prognostic significance. Despite the correlation between serum albumin levels and other nutritional indicators such as prealbumin, total protein and total lymphocyte counts, only serum albumin level was an independent predictor of patient survival.

Conclusions: Serum albumin level is associated with prognosis in glioblastoma patients, although the underlying mechanism is complex because of the role of serum albumin as a nutritional indicator and its involvement in inflammatory responses.

Figure 1

Correlation between preoperative serum albumin levels and other clinical factors in glioblastoma patients. (A) Relationship between preoperative serum albumin levels and adjuvant treatment. For adjuvant treatment: CAG, completely applied group; NAG, not applied group; PAG, partially applied group. (B) Relationship between preoperative serum albumin levels and KPS.

Figure 2

Preoperative serum albumin levels and prognosis. (A, B) Kaplan–Meier survival curves stratified by preoperative serum albumin levels. Survival was significantly lower among patients with low serum albumin (<30 g/L) than in those in the normal range (≥30 g/L; A). Patients with upper normal albumin levels (≥40 g/L) experienced longer survival than patients with lower normal albumin levels (30–40 g/L; B). (C, D) Preoperative serum albumin levels were correlated with 1-year (C) and 2-year (D) survival rates.

Figure 3

Receiver-operator characteristic (ROC) curve and stratified analysis. (A) ROC curve analysis of preoperative serum albumin level. In 214 glioblastoma patients, at the median level (35.35 g/L) of preoperative serum albumin, the discriminative power reached 62.5% sensitivity and 63.7% specificity for short-survival cases (<1 year) versus long-survival cases (>1 year). AUC, area under the curve. (B) Stratified analysis of preoperative serum albumin level and overall mortality. Hazard ratios and 95% confidence intervals in various strata are shown. For adjuvant treatment: CAG, completely applied group; NAG, not applied group; PAG, partially applied group. (C) Preoperatively, serum albumin levels were significantly correlated with prealbumin, total protein levels and total lymphocyte counts.

Figure 4

Immunohistochemistry for IDH1-R132H mutation. (A) Serum albumin levels in patients with or without dexamethasone use. (B) Representative immunohistochemical images of tumors with or without IDH1-R132H mutation (×400). Scale bar: 50 μm.