Utility of clinical, laboratory, and lymph node MYD88 L265P mutation in risk assessment of diffuse large B-cell lymphoma patients.

Background: Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin lymphoma and is characterized by heterogeneity in biology and clinical behavior. Mutations in the myeloid differentiation primary response 88 (MYD88) are found in different lymphoproliferative disorders and are associated with variable clinical and prognostic impact.

Aim: To investigate the frequency of MYD88 L265P mutation and its clinical impact in a cohort of Egyptian DLBCL patients.

Methods: FFPE lymph node samples from 87 DLBCL patients (46 males / 41 females; median age, 58 years) were included and analyzed for MYD88 L265P by an allele-specific PCR.

Results: MYD88 L265P mutations were found in 52 patients (59.8%) out of 87 DLBCL cases. Patients with L265 mutation were significantly younger than non-mutated patients (p = 0.022). None of the patients with the L265P mutation showed a significant association with the clinical parameters of DLBCL. Interestingly, MYD88 L265 mutated patients were found to be significantly correlated with HCV infection (p = 0.037). The median follow-up time across the entire cohort was 26 months. Univariate analysis showed that overall survival (OS) was affected by gender, LDH level, and CNS-IPI scoring (p = 0.048, 0.008, and 0.046, respectively), while disease-free survival (DFS) was affected by B symptoms and LDH level (p =  < 0.000 and 0.02, respectively). However, the MYD88 mutation status and other prognostic factors showed no association with OS or DFS.

Conclusions: Our findings indicate a high frequency of MYD88 L265P mutations in our study population and not associated with prognostic markers or the outcome of the disease.