Impact of repeated operations for progressive low-grade gliomas

Maximal, aggressive resection of diffuse low-grade gliomas (DLGG) is well established as the standard of care in neuro-oncology. The role of repeat resection for tumor progression is unclear.

To assess the role of repeated operation for DLGG, and the effect on malignant transformation and survival.

We conducted a historical cohort study in which all patients undergoing multiple resections of DLGG between the years 1995-2019 were evaluated for overall survival (OS) and time to transformation (TTT). We then compared the outcome of this group with that of a matched control group comprised of patients who underwent only one operation despite being eligible for repeat surgery at tumor progression, but had received non-surgical oncological therapy or declined additional treatment.

Of 607 patients in our departmental DLGG database, 93 patients underwent 2 or more surgeries and had sufficient follow-up and imaging data to be included in the study group. Thirty-eight patients were included in the matched control group. Early (less than 1 year) progression was associated with decreased survival and shorter TTT in the study group. Patients undergoing multiple resections had significantly longer TTT and OS compared to patients who underwent a single surgery. This effect was especially noted in patients who had radiological evidence of tumor transformation.

Repeated resections of LGG are safe and offer survival benefit in select patients. Early progression following resection is associated with worse prognosis. Patients with evidence of radiological transformation may benefit the most from re-resection.