O6-METHYLGUANINE-DNA-METHYLTRANSFERASE (MGMT) EXPRESSION IN PATIENTS WITH GLIOBLASTOMA MULTIFORME.

Expresión de O6-metilguanina-DNA-metiltransferasa (MGMT) en pacientes chilenos con Glioblastoma multiforme

Author
Jiménez, Daniel; Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Servicio de Neurología, Hospital del Salvador, Santiago, Chile

Matamala, José Manuel; Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Instituto de Neurociencia Biomédica (BNI), Facultad de Medicina, Universidad de Chile, Santiago, Chile

Chiti, Alessandra; Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile

Vergara, Carmen; Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile.

Tissera, Claudia; Instituto de Neurocirugía Dr. Asenjo, Santiago, Chile

Melo, Romulo; Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Instituto de Neurocirugía Dr. Asenjo, Santiago, Chile.

Cartier, Luis; Laboratorio de Investigación Biomédica, Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Departamento de Ciencias Neurológicas Oriente, Facultad de Medicina, Universidad de Chile, Santiago, Chile. Servicio de Neurología, Hospital del Salvador, Santiago, Chile

Full text
http://www.revistamedicadechile.cl/ojs/index.php/rmedica/article/view/6137
Abstract
Background: 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. Aim: To evaluate MGMT expression by IHC in tumor tissue of Chilean patients with GBM. Material and methods: 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. Results: 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. Conclusions: Our results are similar to international reports, but we were not able to determine the association between MGMT expression and therapeutic response.
 
Background: 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. Aim: To evaluate MGMT expression by IHC in tumor tissue of Chilean patients with GBM. Material and methods: 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. Results: 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. Conclusions: Our results are similar to international reports, but we were not able to determine the association between MGMT expression and therapeutic response.
 
Metadata
Show full item record