P.021 Surgical management of incidentally discovered diffusely infiltrating glioma

Abstract

Background: Occasionally low grade gliomas (LGGs) are identified incidentally while asymptomatic. The diagnosis of incidental LGGs has become more frequent due to increase in access to medical imaging. While management of these lesions remains controversial, early surgery has been suggested to improve outcome. Methods: All LGGs treated between 2004 and 2016 at our institution were reviewed. Patients with incidentally discovered glioma were identified and retrospectively reviewed. “Incidental” was defined as an abnormality on imaging that was obtained for a reason not attributable to the glioma. Outcomes were measured by overall survival, progression free survival and malignant progression free survival. Results: Thirty-four out of 501 adult patients who were treated for low grade glioma were discovered incidentally. Headache (26%, n=9) and screening (21%, n=7) were the most common indications for brain imaging. The mean duration follow up was 5 years. Twelve patients had disease progression, 5 cases of malignant progression and 4 deaths. Oligodendroglioma was diagnosed in 16 and astrocytoma in 15 patients. Twenty-five (74%) patients had IDH1 mutation and demonstrated prolonged survival. Conclusions: This retrospective cohort of incidentally discovered LGGs were surgically removed with minimal surgical risk. There is improved overall survival likely attributable to the underlying favorable biology of the disease indicated by the presence of IDH1 mutation.