Jiménez Daniel, Matamala José Manuel, Chiti Alessandra, Vergara Carmen, Tissera Claudia, Melo Rómulo, Cartier Luis
Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Laboratorio de neuropatología, Instituto de Neurocirugía Dr. Alfonso Asenjo, Santiago, Chile.
Rev Med Chil. 2018 Jan;146(1):7-14. doi: 10.4067/s0034-98872018000100007.
Patients with Glioblastoma multiforme (GBM) have a five years survival of less than 5%, but the response to chemotherapy with alkylating agents can vary depending on the methylation status of O6-methylguanine-DNA-methyltransferase (MGMT). Genetic testing has limitations for routine use, while immunohistochemistry (IHC) offers a fast and affordable technique but with heterogeneous results in the literature.
To evaluate MGMT expression by IHC in tumor tissue of Chilean patients with GBM.
Tumor samples of 29 patients with a pathological diagnosis of GBM were studied. We performed IHC staining and manual analysis of positive and negative cells for MGMT expression. A cut-off of at least 10% of cells expressing MGMT was used. Demographic and clinical features of patients were obtained from clinical records.
The median number of cells counted per case was 692 (interquartile range [IQR] 492-928). Fifteen cases (52%) were positive for MGMT expression. Median overall survival was 5.3 months (IQR 3.4-12-8). The effect of MGMT expression on the therapeutic response was not studied since only 3 patients received chemotherapy.
Our results are similar to international reports, but we were not able to determine the association between MGMT expression and therapeutic response.
多形性胶质母细胞瘤（GBM）患者的五年生存率低于5%，但对烷化剂化疗的反应可能因O6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）的甲基化状态而异。基因检测在常规应用中有局限性，而免疫组织化学（IHC）提供了一种快速且经济的技术，但文献中的结果存在异质性。
通过免疫组织化学评估智利GBM患者肿瘤组织中MGMT的表达。
研究了29例经病理诊断为GBM患者的肿瘤样本。我们进行了免疫组织化学染色，并对MGMT表达的阳性和阴性细胞进行了手动分析。使用至少10%的细胞表达MGMT作为临界值。患者的人口统计学和临床特征从临床记录中获取。
每例计数细胞的中位数为692（四分位间距[IQR]492-928）。15例（52%）MGMT表达呈阳性。总生存期的中位数为5.3个月（IQR 3.4-12.8）。由于只有3例患者接受了化疗，因此未研究MGMT表达对治疗反应的影响。
我们的结果与国际报告相似，但我们无法确定MGMT表达与治疗反应之间的关联。
