Could upfront temozolomide chemotherapy postpone the intervene of radiotherapy in young patients with high-risk low-grade gliomas?

Abstract

BackgroundLow-grade gliomas that involves eloquent areas are difficult to be removed totally. Standard strategies for these young patients are radiotherapy and chemotherapy after maximum safe resection. Radiotherapy always brings cognitive impairments. We wonder whether temozolomide chemotherapy can postpone the intervene of radiotherapy to protect cognitive function.MethodsPatients underwent temozolomide chemotherapy (75mg/m2/day for 21 days per 28-day for 6 cycles) and were followed up by MRI and cognitive function evaluation. Primary endpoints are objective response rate (ORR), and secondary endpoints are intensity of response (IOR), duration of response (DOR), cognitive function results and the safety of chemotherapy.Results65 patients were recruited with a median follow-up of 39.6 months, and ORR was 37/65(56.92%). IDH mutant patients had better ORR than IDH wildtype patients (64.29% vs 11.11%, p=0.004), and IOR of IDH mutant tumors was more obvious (p=0.023). IDH-mutant group had longer DOR than IDH-wildtype group (median DOR, 52.4 vs 25.8 months; log-rank p=0.0007; HR, 4.269; 95%CI, 3.411 - 47.35), and 1p/19q codeletion group had a longer DOR than 1p/19q retain group (median DOR, 52.4 vs 37.5 months; log-rank p=0.049; HR, 2.369; 95%CI, 1.012 - 5.397). Cognitive function results showed improvement in cognitive function at early stage compared with radiotherapy.ConclusionIDH mutation was a predictive factor for better temozolomide response. Cognitive function evaluation proved that temozolomide chemotherapy could avoid cognitive impairments at early stage. We propose that young patients with IDH mutation can use upfront chemotherapy to postpone radiotherapy until progression to avoid potential cognitive impairments.