Albumin levels and Prognostic Nutritional Index in glioblastoma.

Abstract

e13567 Background: Albumin levels are widely used to estimate patients’ nutritional status. Low perioperative albumin levels are associated with worse outcomes. Moreover, Prognostic Nutritional Index (PNI), which is calculated from serum albumin levels and peripheral blood lymphocyte count as follows: PNI = (Albumin x 10) + (0.005 x ALC), has been used to predict both short and long term outcomes in patients with wide variety of tumors. The primary objective of this study was to characterize perioperative albumin levels and PNI in newly diagnosed GBM patients. Secondary objectives included associations between albumin levels and PNI on progression free survival (PFS) and overall survival (OS). Methods: We retrospectively reviewed 568 newly diagnosed GBM patients who underwent surgery followed by standard of care chemoradiation. We analyzed the association between albumin and PNI on age, sex, MGMT methylation status, and extent of surgical resection on PFS and OS using a multivariate Cox proportional hazard model. Results: Of the 568 patients collected, 355 (62.5%) were males, 158 (27.8%) had gross total resection of the tumor, and 197(42.5%) were MGMT methylated. Both albumin and PNI were associated with OS but not PFS. The hazard ratio (HR) for OS among the top 2 quartiles of both albumin level and PNI were significantly higher than the bottom two quartiles. The median albumin level was 4.0 and the median PNI was 40. The point for significant high hazard ratio (HR) was around median value for both Albumin and PNI based on restricted cubic spine Cox regression models. The Kaplan-Meir (KM) estimated median OS was 15.2 months for albumin > 4, and 7.6 for albumin ≤4. The KM estimated median OS was 14.6 months for PNI > 40, and 5.7 for PNI≤40 (P logrank < 0.001 for both). While controlling for other factors that may also be associated with early death including age, gender, surgery type and MGMT status, HR = 1.9 (95% CI = 1.4- = 2.6) for Albumin < 4, and HR = 2.1 (95% CI = 1.5- 3.0) for PNI < 40 compared to their counterpart. Conclusions: Glioblastoma patients with perioperative albumin > 4 had a median OS of 15.2 months and 7.6 months for albumin ≤4, and a median OS of 14.6 months for PNI > 40 and 5.7 months for PNI≤40 (P logrank < 0.001 for both).