Clinical significance of MYD88 non-L265P mutations in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a group of heterogeneous tumors with different molecular traits and clinical features. MYD88 is an oncogene that activates the nuclear factor κB pathway in DLBCL. MYD88 L265P mutation frequently occurs in DLBCL with poor prognosis, while the clinical significance of non-L265P mutations needs to be clarified. Next-generation sequencing was performed on a cohort of 356 patients with DLBCL to investigate the impact of MYD88 mutation. Ten MYD88 mutated variants were detected in 32% (114/356) of the cases. V217F, S219C, S222R, M232T, S243N, and T294P were identified as pathogenic variants. MYD88 non-L265P mutations occurred less than L265P mutation in DLBCL of the central nervous system and breast tissue. The coexistence of MYD88 non-L265P mutations with PIM1 mutation was also less than that of L265P mutation. The progression-free survival in patients with DLBCL with MYD88 non-L265P mutation was statistically better than in patients with MYD88 L265P mutation. The interpretation of variants of MYD88 mutation offers a precise guide for the management of DLBCL.