Supratentorial low grade astrocytoma: prognostic factors, dedifferentiation, and the issue of early versus late surgery

摘要

BACKGROUND—A retrospective study of patients withlow grade astrocytoma was carried out because the best management ofsuch patients remains controversial. Prognostic factors were identifiedby multivariate analysis. Special attention was paid to the effect ofextent and timing of surgery.
METHODS—Ninety patients with low grade astrocytomawere studied. Seventy two patients had resective surgery, 15 had adiagnostic biopsy only, and three patients had resective surgery afterinitial biopsy.
RESULTS—Significant prognostic factors forsurvival were age, preoperative neurological condition, epilepsy as thesingle sign, extent of surgery, and histology. The extent of surgerywas highly significant on univariate analysis (p=0.002); however, aftercorrection for age and preoperative symptoms this was considerablyreduced (p=0.04). A subgroup of 30 patients with epilepsy as theirsingle presenting symptom was identified. Thirteen of these patientswere treated immediately after diagnosis, whereas the other 17 patientswere initially followed up and treated only after clinical orradiological progression. Survival in both groups was identical (63%survival rate after five years) and much better than survival for thewhole group (27% survival rate after five years). Malignantdedifferentiation was observed in 25 (70%) of 36 patients who werereoperated, after a median period of 37 months. This period was 41 months for the subgroup of patients with epilepsy only and 28 monthsfor the remaining patients.
CONCLUSIONS—Due to the retrospective nature of thestudy only restricted conclusions can be drawn. Low grade glioma withepilepsy as the single symptom has a much better prognosis than ifaccompanied by other symptoms. This prognosis is not influenced by thetiming of surgery. It seems, therefore, safe to defer surgery untilclinical or radiological progression in low grade glioma with epilepsy only.