O'Neill, Brian Patrick

Abstract Purpose: Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin lymphoma confined to the central nervous system. Whether there is a PCNSL-specific genomic signature and, if so, how it differs from systemic diffuse large B-cell lymphoma (DLBCL) is uncertain. Experimental Design: We performed a comprehensive genomic study of tumor samples from 19 immunocompetent PCNSL patients. Testing comprised array-comparative genomic hybridization and whole exome sequencing. Results: Biallelic inactivation of TOX and PRKCD was recurrently found in PCNSL but not in systemic DLBCL, suggesting a specific role in PCNSL pathogenesis. In addition, we found a high prevalence of MYD88 mutations (79%) and CDKN2A biallelic loss (60%). Several genes recurrently affected in PCNSL were common with systemic DLBCL, including loss of TNFAIP3, PRDM1, GNA13, TMEM30A, TBL1XR1, B2M, CD58, activating mutations of CD79B, CARD11, and translocations IgH-BCL6. Overall, B-cell receptor/Toll-like receptor/NF-κB pathways were altered in >90% of PNCSL, highlighting its value for targeted therapeutic approaches. Furthermore, integrated analysis showed enrichment of pathways associated with immune response, proliferation, apoptosis, and lymphocyte differentiation. Conclusions: In summary, genome-wide analysis uncovered novel recurrent alterations, including TOX and PRKCD, helping to differentiate PCNSL from systemic DLBCL and related lymphomas. Clin Cancer Res; 21(17); 3986–94. ©2015 AACR.

There has been an overall decline in the United States incidence of Primary CNS Lymphoma (PCNSL) from 1998 to 2008. This study's intent was to characterize the cohorts contributing to it. First, calculated the PCNSL incidence rates from nine Surveillance, Epidemiology, and End Results (SEER) registries for time period 1973 to 2008. Second, examined the time trends overall and by age and gender. Third, used 1992–2008 SEER data from the same registries to obtain overall trends for diffuse large B‐cell lymphoma (DLBCL). Last, rates were age‐adjusted to the 2000 US standard population and reported per 100,000 person‐years. Rates continued to increase in women at all ages and men aged 65 and older. In men aged 20–39 and 40–64 years incidence rates peaked in 1995 and then declined dramatically, stabilizing after 1998. The trends in the incidence of PCNSL over this time frame were significantly different from DLBCL for ages 20–39 (P < 0.001) and 40–64 (P < 0.001) years but were not different for the 65 years and older age group (P = 0.99). The overall PCNSL incidence rate declined since 1995 and was driven primarily by the changing incidence in young and middle‐aged men. The rate has continued to increase in men aged 65 years and older and in women. The trends in incidence in the younger age groups over this time period did not parallel those observed for DLBCL. Am. J. Hematol. 88:997–1000, 2013. © 2013 Wiley Periodicals, Inc.