The effect of operations in patients with recurrent diffuse low-grade glioma: A qualitative systematic review

The role of operation for patients with recurrent diffuse low-grade glioma (DLGG) is controversial. A few studies compared the effectiveness between surgery and other treatments for those patients. We did a systematic review for the effects of reoperation for recurrent DLGG. We searched the following databases from 1990 to 2018: Medline, Cochrane Library, Scopus and Opengrey, including researches about reoperation for recurrent DLGG, regardless of comparison and study design. The Newcastle-Ottawa scale (NOS) was used for quality assessment. Ten studies with 358 participants met the criteria. Due to lack of survival data about non-operated group, we failed to analyze the effect of reoperation. The risk bias of included studies was acceptable except the comparability. However, we found 48.4 % (155/320) of patients underwent gross resection and the safety was acceptable. About 1/3 received adjuvant therapy and 41.9 % (125/298) got histologically progressed. In a word, few studies reported the survival data of recurrent DLGG patients received reoperation. Most were young adults and half of them experienced a histological progress. But there are still a lot of shortages of the existing studies and more researches on the reoperation efficacy in recurrent DLGG are needed.