Introduction: Presently, there are no clear evidence-based recommendations for the surgical management of recurrent lower-grade gliomas (LGGs). In our work, we evaluated the oncological and functional (neurological, neuropsychological, quality of life evaluation) outcomes of a series of LGGs treated in a 5-year period. The aim was to identify factors associated with better outcomes, to be implemented in the treatment decision making process.
Methods: In our retrospective analysis, 738 recurrent LGGs were included (follow-up 7.9 years; IQR:6-9).
Results: Overall, 521 patients (70.6%) recurred. Of those treated with open resection 63.5% relapsed. Tumor progression was histologically confirmed in 72.5% of cases, no valuable tumor (effect of treatment) in 27.5% of cases, histo-molecular conversion in 7.5% of cases, malignant transformation in 38.7% of cases. Among the clinical, imaging, and molecular factors analyzed, longest PFS of recurrent tumors was associated with patient functional status, previous PFS, previous EOR, speed of growth (>6 mm/year), atypical type of recurrence, tumor grade, presence of codeletion, and CDNK status. Best functional outcome associated with surgical resection, EOR, and tumor grade; worst functional outcome with RT and malignant transformation. Longest OS associated with previous EOR, surgical resection, tumor grade, presence of co-deletion. Malignant transformation was associated to previous EOR. Among patients submitted solely to tumor biopsy, changes in MGMT methylation status and in IDH status were observed in 65.3% and 5% of cases, respectively. Modification in IDH status was associated with atypical (distant) type of recurrence. New histo-molecular profile helped in the treatment decision making process.
Conclusion : Surgical resection of recurrent LGGs is associated with longer PFS and OS. Tumor biopsy should be considered, when surgery considered unfeasible, to tailor adjuvant treatment.
