Correlation Between MGMT Gene Promoter Mathylation And Efficacy Of Temozolomide In Patients With Malignant Gliomas

ObjectiveIn this study,the promoter methylation status of 06-methylguanine-DNA methyltransferase(MGMT)gene in malignant glioma tissues was detected to investigate its effect on the efficacy and prognosis of temozolomide chemotherapy in order to provide clinical basis for the selection of predictable and individualized chemotherapy regimen.MethodsObject of observation:Collected from may 2014 to may 2016 period,accepted surgical treatment,and were confirmed by pathology according to the WHO classification of tumors of the central nervous system in patients with malignant brain gliomas(WHO grade ?,WHO grade ?)diagnosed 30 cases,including 17 male and 13 female,aged from 26 to 82 years,anaplastic astrocytoma(WHO grade ?)7 cases,anaplastic oligodendrocytoma(WHO grade ?)4 cases,glioblastoma(WHO grade ?)19 cases.Observation methods:MGMT gene promoter methylation status was detected by bisulfite sequencing PCR(BSP)in glioma tumor tissues.The patients was divided into methylation group and unmethylation group according to the detection results.30 cases of patients with malignant gliomas were treated by neurosurgery,3-dimensional conformal radiotherapy(3DCRT)or intensity modulated radiotherapy(IMRT)synchronized with temozolomide chemotherapy and then 6 cycles of adjuvant chemotherapy with temozolomide.Thirty patients with malignant gliomas were evaluated for their short-term efficacy and drug safety according to the 2009 RECIST and CT('AE-v4.0.Tracking and recording their progression-free survival time,and observe the relationship of MGMT gene promoter methylation with the age,gender,KPS score,pathological grade and extent of surgical resection of the patients.Statistical methods:The data were analyzed by SPSS 17.0 and excel statistical software.Fisher exact probability method was used to analyze the relationship between MGMT gene promoter methylation status and clinical pathological characteristics of patients such as age,gender,KPS score,pathological grade and extent of surgical resection,and the relationship between MGMT gene promoter methylation status and short-term efficacy(objective effective rate,disease control rate)of patients.Kaplan-Meier survival curves were used to indicate the relationship between MGMT gene promoter methylation status and progression-free survival time in patients.Log-rank test were used to measure the overall comparison and drawe survival curves.Difference between groups have statistical significance if p<0.05Results1.The methylation rate of MGMT gene promoter was 73.3%(22/30)and the unmethylation rate was 26.7%(8/30)in malignant glioma.2.There was no statistical difference of MGMT gene promoter methylation status according the grouping way of male and female,? 50 years old and<50 years old,KPS>80 points and<80 points,WHO grade III and WHO grade IV,tumor total and subtotal resection(p>0.05).3.The short-term curative efficacy and disease control in MGMT gene promoter methylation group were significantly superior to MGMT gene promoter unmethylation group(?2=4.26,P=0.039;?2=7.27,P=0.007).The progression-free survival time of MGMT gene promoter methylation group was significantly longer than that of MGMT gene promoter unmethylation group(?2=9.386,P=0.002).4.None of the patients showed significant adverse reactions.Conclusion1.The methylation status of MGMT gene promoter was not significantly correlated with age,gender,KPS score,pathological grade and extent of surgical resection.The methylation status of MGMT gene promoter in malignant glioma is closely related to the prognosis of patients treated with temozolomide,which can be used as an indicator for clinical prognosis of patients with malignant glioma.2.BSP is a reliable method to detect MGMT gene promoter methylation status.The detection of MGMT gene promoter methylation is of great significance in guiding patients with malignant glioma to formulate individualized chemotherapy regimen.