The impact of MYD88 and PIM1 in mature large B-cell non-Hodgkin lymphomas: Defining element of their evolution and prognosis.

Abstract

Sequence studies of the entire exome and transcriptome of lymphoma tissues have identified MYD88 and PIM1 as involved in the development and oncogenic signaling. We aimed to determine the frequency of MYD88 and PIM1 mutations, as well as their expressions in conjunction with the clinicopathological parameters identified in mature large B-cell non-Hodgkin lymphomas. The ten-year retrospective study included 50 cases of mature large B-cell lymphoma, diagnosed at the Pathology Department of the Emergency County Hospital of Constanţa and Săcele County Hospital of Brasov. They were statistically analyzed by demographic, clinicopathological, and morphogenetic characteristics. We used a real-time polymerase chain reaction technique to identify PIM1 and MYD88 mutations as well as an immunohistochemical technique to evaluate the expressions of the 2 genes. Patients with lymphoma in the small bowel, spleen, brain, and testis had a low-performance status Eastern Cooperative Oncology Group (P = .001). The Eastern Cooperative Oncology Group performance status represented an independent risk factor predicting mortality (HR = 9.372, P < .001). An increased lactate dehydrogenase value was associated with a low survival (P = .002). The international prognostic index score represents a negative risk factor in terms of patient survival (HR = 4.654, P < .001). In cases of diffuse large B-cell lymphoma (DLBCL), immunopositivity of MYD88 is associated with non-germinal center B-cell origin (P < .001). The multivariate analysis observed the association between high lactate dehydrogenase value and the immunohistochemical expression of PIM1 or with the mutant status of the PIM1 gene representing negative prognostic factors (HR = 2.066, P = .042, respectively HR = 3.100, P = .004). In conclusion, our preliminary data suggest that the oncogenic mutations of PIM1 and MYD88 in our DLBCL cohort may improve the diagnosis and prognosis of DLBCL patients in an advanced stage.