Prognostic impact of MYD88 mutation, proliferative index and cell origin in diffuse large B cell lymphoma

Diffuse large B-cell lymphoma, among non-Hodgkin lymphomas, is one of the most frequent subtypes. Clinical laboratory data and post-treatment outcomes are scarce in the Brazilian population.

The main objective of this retrospective study was to assess the impact of tumor markers, including the Myeloid differentiation primary response 88 (MYD88) mutation.

Eighty-three patients were included and treated with R-CHOP or R-CHOP-like regimens.

Median age was 64-years old and 58% were female patients. The median follow-up was 42 months. The progression free survival (PFS) at this time was 63% and overall survival (OS), 66%. In the patients with tumors expressing Myc proto-oncogene protein (MYC) and B-cell lymphoma 2 (BCL2), assessed by immunohistochemistry (IHC), known as dual protein expressers, median post-progression survival was 31 (15-45) months. An increased proliferative index were associated with a high rate of progression (hazard ratio 2.31 [95% confidence interval [1.05-5.12]; p = 0.04). The cell of origin (COO), identified by IHC, was not able to predict PFS (p = 0.76). The MYD88 L265P mutation was present in 10.8% (9/83) of patients and did not show a prognostic correlation.

In conclusion, the MYD88 mutation, although an important tool for diagnosis and a possible target drug, presented at a low frequency and was not a prognostic marker in this population.