Low grade meth.

One of the great ironies of the treatment approach most commonly employed for low-grade gliomas (LGG) is that neither the chemo (temozolomide) nor the radiation dose (54 Gy) is directly derived from the randomized trials that support their use. In fact, RTOG 0424 is the only LGG trial that actually used this approach—but in a phase 2 setting. To make the most of what we got, a post-hoc analysis on 0424 looked at the impact of MGMT methylation on outcomes. Now remember, for LGG, IDH mutation and 1p19q codeletion are routinely tested but not MGMT methylation. Among the nearly 60% of patients with MGMT methylation status available, roughly 75% were methylated and were enriched for oligodendrogliomas. Even in the presence of IDH mutations, MGMT methylation was associated with improved overall survival. TBL: Go ahead and add MGMT methylation to your low- as well as high-grade glioma neuropathology checklist because its prognostic independent of IDH mutation and 1p19q codeletion status. | Bell, JAMA Oncol 2018