The presence of an MYD88 mutation or protein expression and PD-1/PD-L1 expression were not associated with survival outcomes for patients with primary central nervous system lymphoma (PCNSL), an analysis found. The results were published online in June 2019 in Leukemia & Lymphoma.

The analysis included 53 adult patients who received a diagnosis of PCNSL between 2000 and 2016 at Vanderbilt University Medical Center, Nashville, Tennessee, or the University of North Carolina Medical Center at Chapel Hill. All cases had archival tissue specimens available. Electronic medical records were retrospectively reviewed to obtain clinical, laboratory, and outcome data.

Cases included patients with a median age of 59 years (range, 21-84 years) at diagnosis and about half were male and half were female. Of the 53 cases, 15 had PD-L1 and/or PD-1–expressing lymphoma cells and 13 had Epstein-Barr virus (EBV)–associated PCNSL.

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Of the EBV-positive cases, most had human immunodeficiency virus (HIV) and all did not harbor a MYD88 L265P mutation. “All tumor PD-L1–positive cases were also EBVpos and lacked MYD88 L265P mutation,” the study authors wrote.

Nearly all cases (94%) had MYD88 protein expression, with 69% expressing a high level. In contrast, 13 of 33 tested patients (39%) carried the MYD88 L265P mutation, indicating no correlation between the presence of high MYD88 expression and MYD88 L265P mutation (P =.12).

The analysis explored potential associations between survival outcomes and HIV status, MYD88 L265P mutation, MYD88 protein expression, PD-L1 or PD-1 expression, and tumor microenvironment PD-L1 expression. The investigators found that none of these factors were predictive of progression-free survival or overall survival.

“We report for the first time how MYD88 protein expression in PCNSL relates to an underlying MYD88 L265P mutation,” the study authors wrote. “In addition, like prior studies of EBVpos lymphoma, these results support the hypothesis that EBV infection has a distinct effect on tumor microenvironment and oncogenic landscape mediated through viral components rather than underlying genetic mutations.”

Reference

Sethi TK, Kovach AE, Grover NS, et al. Clinicopathologic correlates of MYD88 L265P mutation and programmed cell death (PD-1) pathway in primary central nervous system lymphoma [published online June 11, 2019]. Leuk Lymphoma. doi: 10.1080/10428194.2019.1620942