The effect of allergy on survival was significant (p = 0.025, HR 0.525, 95% CI 0.299-0.924), independent of the effect of chromosome 1p (p < 0.001, HR 93.4, 95% CI 16-546) and 19q (p = 0.801, HR 1.2, 95% CI 0.23-6.9) codeletion or TP53 mutation (p = 0.015, HR 2.7, 95% CI 1.2-5.9), unrelated to TERT expression (p = 0.365, HR 1.1, 95% CI 0.89-1.4) or ATRX mutation (p = 0.904, HR 1.04, 95% CI 0.51-2.14), independent of tumor grade (grade 2 versus grade 3, p = 0.004, HR 2.2, 95% CI 1.3-3.8), not independent of histology (oligodendroglioma and oligoastrocytoma, NOS versus astrocytoma, p = 0.08, HR 0.62, 95% CI 0.36-1.1).
The molecular classification on the basis of IDH1/2 mutation, TP53 mutation, and 1p/19q loss has power similar to histological classification and avoids the ambiguity inherent to the diagnosis of oligoastrocytoma.
The presence of TP53 mutations was associated with shorter survival of patients with low-grade diffuse gliomas (log-rank test; P=0.047), but when each histological type was analyzed separately, an association was observed only for oligoastrocytoma ( P=0.05).
Loss of 1p and 19q were associated with LGO but not LGOA (P =.009), were inversely associated with p53 detection, and were not associated with response to PCV (possibly because of the small sample size).