Velocity of tumor spontaneous expansion predicts long-term outcomes for diffuse low-grade gliomas

Abstract

BackgroundSupratentorial diffuse low-grade gliomas present a slow macroscopic tumor growth that can be quantified through the measurement of their velocity of diametric expansion. We assessed whether spontaneous velocity of diametric expansion can predict long-term outcomes as a categorical variable and as a continuous predictor.MethodsA total of 407 adult patients with newly diagnosed supratentorial diffuse low-grade gliomas in adults were studied.ResultsThe mean spontaneous velocity of diametric expansion before first-line treatment was 5.8 ± 6.3 mm/year. During the follow-up (mean, 86.5 ± 59.4 months), 209 patients presented a malignant transformation, and 87 died. The malignant progression-free survival and the overall survival were significantly longer in cases of slow velocity of diametric expansion (median, 103 and 249 months, respectively) than in cases of fast velocity of diametric expansion (median, 35 and 91 months, respectively; P <4, ≥4 and <8, ≥8 and <12, ≥12 mm/year) was an independent prognostic factor for malignant progression-free survival (P