Abstract 2394: Subpopulation of infiltrating lymphocyte and MGMT methylation in brain tumor prognosis

Abstract

Abstract Background: Clinicopathological features including MGMT methylation have been correlated to prognosis in Glioblastoma (GBM). Tumor infiltrating lymphocytes (TILs) are predictive of clinical outcome in different malignancies. We evaluated association between clinicopathological features including MGMT methylation and IHC infiltrating immune cell subpopulations in 43 resected GBM cases who came from 2008 to 2013. Methods: A prospective evaluation of TIL (CD3, CD4, CD8 and CD20) and macrophages (CD68 and CD163) through H&E was performed by a pathologist and evaluated Immune cell subpopulations was evaluated through scanning, and software analysis (BX63 Olympus and TissueMorph-Visionpharm) with pathologist support. MGMT evaluation was prospectively performed by bisulphyte PCR test in paraffin samples. Results: Median age was 47.9 y, men (51.2%), Karnofsky scale 90% (62.8%), median tumor size of 5.1 cm, and partial/ complete tumor resection (22/21). Methylation MGMT test was performed in 31 cases and 17 showed un- methylated, 4 partial methylated and 10 methylated. TILs evaluation by HE showed low- intensity (29 cases), middle- intensity (1) and high- intensity level (9). Pattern of distribution was focal (9 cases), multi- focal (13) and diffuse (17). Median CD3, CD4, CD8, CD20, CD68 and CD163 were 1.6%, 0.032%, 1.6%, 0.03%, 9.1% and 2.2% (regarding total cells), respectively. Higher CD163 level was associated to male (p=0.03) and larger size (p=0.05). Higher levels of CD8 was associated to larger size (p=0.05). Higher CD8 and CD20 was associated to unmethylated MGMT (p=0.041 and 0.013). Median follow- up was 14 months. Only total resection (p<0.05) and MGMT methylation (p<0.05) was associated to outcome. Lymphocyte infiltration (H&E) was not associated to outcome: Lymphocyte intensity (p=0.703), distribution (p=0.61). Longer OS was associated to lower CD4 levels (p=0.01). Conclusion: Tumor Infiltrating immune cell are not common in GBM, CD8 and CD20 was associated to unmethylation, and CD4 and MGMT methylation were associated to prognosis. Citation Format: Carlos Castaneda, Miluska Castillo, Carolina Belmar-Lopez, Sandro Casavilca, Luis Angel Bernabe, Tatiana Vidaurre. Subpopulation of infiltrating lymphocyte and MGMT methylation in brain tumor prognosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2394. doi:10.1158/1538-7445.AM2017-2394