Survival analysis of radiotherapy alone versus radiotherapy combined with temozolomide chemotherapy for low-grade gliomas: a meta-analysis

Abstract Purpose: According to the WHO classification, low-grade gliomas (LGGs) are slow-growing primary brain tumors, including grades I and II; accounting for 25-30% of adult gliomas, including astrocytomas,Oligodendrogliomas,angiocentric gliomas, among others, have widely variable prognosis, with survival ranging from less than one year to more than 20 years after initial diagnosis. Generally, surgical resection is the main method, Postoperative adjuvant radiotherapy (RT), observation, chemotherapy or chemoradiotherapy (combined with temozolomide (TMZ), CRT). This study aimed to compare the efficacy of radiotherapy alone and radiotherapy combined with temozole chemotherapy in low-grade gliomas. Methods: Eligible literature was searched in PubMed, the Cochrane Library database and Embase from database start to August 2022. Primary outcome measures were rigorously extracted after screening for available studies that met inclusion and exclusion criteria. Survival data were determined and extracted with odds ratios (HR) with 95% confidence intervals (CI) using a fixed-effects model, and if HR was not reported in the article, we used Engauge Digitizer 11.3 (QT) to extract events from Kaplan-Meier survival curves time data. Results The efficacy of RT versus CRT in low-grade gliomas was evaluated using a forest plot made by revman 5.3. Results: A total of 6 articles were included, including 3 case-control studies, 1 cohort study, and 2 RCTs, including a total of 1310 patients, including 133 conservative treatment cases, 17 cases of TMZ chemotherapy alone, 424 cases of RT treatment alone, and CRT treatment. 736 cases. Our results showed that CRT significantly improved OS (HR: 0.62 95%CI 0.51-0.75; P<0.00001) and PFS (HR: 0.66 95%CI 0.53-0.84; P =0.0007). Conclusions: In conclusion, the addition of temozolomide chemotherapy to radiotherapy for postoperative adjuvant therapy of low-grade glioma improves OS and FPS. In addition to improving survival and progression-free survival, future research needs to better understand the risk and mechanisms of TMZ-induced hypermutation in low-grade gliomas, and the focus should be on the prevention of malignant transformation.