McPhail, Ellen Darcy

AbstractWaldenström macroglobulinemia (WM) is an immunoglobulin M‐associated lymphoma, with majority of cases demonstrating MYD88 locus alteration, most commonly, MYD88L265P. Owing to low prevalence of the wild‐type (WT) MYD88 genotype in WM, clinically relevant data in this patient population are sparse, with one study showing nearly a 10‐fold increased risk of mortality in this subgroup compared to patients with MYD88L265P mutation. We studied a large cohort of patients with MYD88L265P and MYD88WT WM, evaluated at Mayo Clinic, Rochester, between 1995 and 2016, to specifically assess the impact of these genotypes on clinical course. Of 557 patients, MYD88L265P mutation status, as determined by allele‐specific polymerase chain reaction, was known in 219, and 174 (79%) of those exhibited MYD88L265P, 157 of 174 patients had active disease. Of 45 (21%) patients with MYD88WT genotype, 44 had active disease. The estimated median follow‐up was 7.0 years; median overall survival was 10.2 years (95% CI: 8.4‐16.5) for MYD88L265P versus 13.9 years (95% CI: 6.4‐29.3) for the MYD88WT (P = 0.86). The time‐to‐next therapy from frontline treatment and the presenting features were similar in the two patient populations. For patients with smoldering WM at diagnosis, the median time‐to‐progression to active disease was 2.8 years (95% CI: 2.2‐3.8) in the MYD88L265P cohort and 1.9 years (95% CI: 0.7‐3.1) in the MYD88WT cohort (P = 0.21). The frequency of transformation to high‐grade lymphoma, or the development of therapy‐elated myelodysplastic syndrome was higher in the MYD88WT cohort (16% versus 4% in the MYD88L265P, P = 0.009). In conclusion, MYD88L265P mutation does not appear to be a determinant of outcome, and its presence may not be a disease‐defining feature in WM. Our findings warrant external validation, preferably through prospective studies.

Abstract Background. The salivary gland is one of the most common sites involved by nongastric, extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). A large series of patients with long-term follow-up has not been documented. This multicenter, international study sought to characterize the clinical characteristics, treatment, and natural history of salivary gland MALT lymphoma. Methods. Patients with biopsy-confirmed salivary gland MALT lymphoma were identified from multiple international sites. Risk factors, treatment, and long-term outcomes were evaluated. Results. A total of 247 patients were evaluated; 76% presented with limited-stage disease. There was a history of autoimmune disorder in 41%, with Sjögren disease being the most common (83%). Fifty-seven percent of patients were initially treated with local therapy with surgery, radiation, or both; 37 of patients were treated with systemic therapy initially, with 47% of those receiving rituximab; and 6% of patients were observed. The median overall survival (OS) was 18.3 years. The median progression-free survival (PFS) following primary therapy was 9.3 years. There was no difference in the outcomes between patients receiving local or systemic therapy in first-line management. On multivariate analysis, age <60 years and low to intermediate international prognostic index were associated with improved OS and PFS; Sjögren disease was associated with improved OS. Conclusion. Salivary gland MALT lymphoma has an excellent prognosis regardless of initial treatment, and patients with Sjögren disease have improved survival. Risks for long-term complications must be weighed when determining initial therapy. Implications for Practice: Patients with salivary gland extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) have an excellent prognosis, particularly those with associated Sjögren's disease. A wide range of available therapies may provide similar durable rates of disease control and survival. Therefore, an important goal in selection of therapy should be to minimize morbidity from treatment. When determining initial therapy for these patients, practitioners should consider the potential side effects and long-term toxicities of treatment.

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.

SummaryHighly sensitive flow cytometry studies may incidentally identify B cell clones when used to assess plasma cell clonality in bone marrows. Clinical history, which can help differentiate related clones (low grade B cell lymphoma with plasmacytic differentiation/LBCL‐PD) from unrelated ones (plasma cell proliferative disorder (PCPD) with an unrelated B cell clone), is often unavailable in referred specimens. We sought to identify morphologic or phenotypic features that would help predict the significance of these clones in the absence of history. We included only cases with identical light chain B and plasma cell clones, as determined by 6‐color flow cytometry with additional DNA ploidy analysis, in which the relationship between clones could be established by review of medical records. There were 26 cases; 18 were related (14 were Waldenstrom macroglobulinemia) and eight were unrelated (seven multiple myeloma). Features seen exclusively in LBCL‐PD include CD19+/CD45+ clonal plasma cell phenotype (66·7%, P = 0·0022) and morphologic features such as paratrabecular bone marrow involvement, increased mast cells, and plasma cells surrounding B‐cell nodules. Aneuploidy was identified exclusively in PCPD cases (75%, P = 0·000028). We conclude that CD19+/CD45+ clonal plasma cell phenotype and aneuploidy are useful in distinguishing related clones (LBCL‐PD) from unrelated clones (PCPD).

Instruction in hematopathology at Mayo Medical School has evolved from instructor‐guided direct inspection under the light microscope (laboratory method), to photomicrographs of glass slides with classroom projection (projection method). These methods have not been compared directly to date. Forty‐one second‐year medical students participated in this pilot study, a prospective, randomized, crossover study measuring educational performance during a hematology pathophysiology course. The students were randomized to one of two groups. All students received the same didactic lectures in the classroom and subsequent case‐based review of peripheral blood smears using either laboratory or projection methods, on day one with a crossover to the other method on day two. Pre‐ and post‐test examinations centered on morphology recognition measured educational performance on each day, followed by a questionnaire identifying the student's favored method. There was no significant difference in the pre‐test and post‐test scores between the two teaching methods (rank‐sum P = 0.43). Students overwhelmingly preferred the projection method and perceived it as superior (76%), although post‐test scores were not significantly different. Student's recommended method was split with 50% favoring the projection method, 43% favoring a combined approach, and 23% noting logistical challenges to the laboratory. In this study, the laboratory and projection method were equivalent in terms of educational performance for hematopathology among medicals students. A classroom‐based approach such as the projection method is favored, given the large class sizes in undergraduate medical education, as well as the ergonomic challenges and additional resources required for large group instruction in a laboratory setting. Anat Sci Educ 7: 130–134. © 2013 American Association of Anatomists.

AbstractGenetic aberrations, including trisomies 3 and 18, and well-defined IGH translocations, have been described in marginal zone lymphomas (MZLs); however, these known genetic events are present in only a subset of cases. Here, we report the cloning of an IGH translocation partner on chromosome X, t(X;14)(p11.4;q32) that deregulates expression of an poorly characterized orphan G-protein–coupled receptor, GPR34. Elevated GPR34 gene expression was detected independent of the translocation in multiple subtypes of non-Hodgkin lymphoma and distinguished a unique molecular subtype of MZL. Increased expression of GPR34 was also detected in tissue from brain tumors and surface expression of GPR34 was detected on human MZL tumor cells and normal immune cells. Overexpression of GPR34 in lymphoma and HeLa cells resulted in phosphorylation of ERK, PKC, and CREB; induced CRE, AP1, and NF-κB–mediated gene transcription; and increased cell proliferation. In summary, these results are the first to identify a role for a GPR34 in lymphoma cell growth, provide insight into GPR34-mediated signaling, identify a genetically unique subset of MZLs that express high levels of GPR34, and suggest that MEK inhibitors may be useful for treatment of GPR34-expressing tumors.

Abstract Introduction: Only few genetic studies have been performed in PCNSL, partly due to the rarity of the tumors and the limited amount of available tissue. Unlike nodal DLBCL, PCNSL is poorly understood in terms of its precise histogenetic origin and molecular pathogenesis. It is still a matter of debate whether PCNSL differs from nodal DLBCL with respect to their molecular features and pathogenesis and also if there is a genomic signature PCNSL-specific. Materials and Methods: To determine the pattern of genetic alterations, 17 immunocompetent (EBV-, HIV-) PCNSL were analyzed by aCGH. Seven cases were analyzed using fresh tumor samples and 10 using formalin-fixed paraffin embedded (FFPE) tissues. B-cell differentiation status was characterized by immunostains for CD10, MUM-1, and BCL-6. The aCGH profile from PCNSL cases was compared with aCGH data obtained from 59 nodal DLBCL. Results: We found a complex karyotype with a median of 21 copy-number abnormalities (CNA) per case (range 10-49). Overall, 18 regions (10 losses and 8 gains) were affected in >20% of cases. Loss of 9p21 (CDKN2A) was the commonest CNA (82% of cases). Other common CNAs were loss of 6q23.3 (TNFAIP3; 59%), 6p21 (HLA genes; 53%), 6q21 (PRDM1; 47%) and gain of 12q21-q24 (53%), 7q21-q31 (35%) and 19q13 (35%). Five novel recurrent focal CNAs were found in PCNSL; loss of 3p21.31, 3q26.32, 10p15.3-p14, 12q24.31 and 16q12.1-q21 (29% of cases each). All of them, excluding –16q12.1-q21, were found either in less than 5% or absent in nodal DLBCL, thus suggesting to be unique to PCNSL. Recurrent homozygous deletions were found in CDKN2A, TMEM30A, TOX and CD58, the latter two involved in T-cell development and activation. CD58 was also recurrently affected by small focal deletions in the Ig-like C2-type domain. Furthermore, DNA sequencing analysis showed missense mutations in the Toll/IL-1 receptor domain of MYD88 in 35% of PCNSLs. Another 34 genes, including B2M, ETV6, MHC class II genes, PRDM1, and TNFRSF10A were homozygously deleted. Bioinformatics analysis including the most commonly affected genes showed an enrichment of networks associated with immune response, NF-kB pathway, proliferation, regulation of the apoptosis and lymphocyte differentiation and activation. Conclusions: We showed evidence of a highly complex genome and identified a subset of genes with potential relevance in PCNSL pathogenesis. The genomic profile described here reinforces the existence of a specific molecular signature in PCNSL, thus helping to genetically differentiate this entity from the nodal DLBCL and related lymphomas. Additionally, the results obtained from FFPE samples are encouraging and larger archival tissue collections can now be analyzed in order to complement the still fragmented knowledge we have of the genetic basis of the disease. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5081. doi:1538-7445.AM2012-5081

Abstract Objective. Molecularly distinct PCNSL signatures with divergent clinical behavior are now recognized. Implied within this heterogeneity are mechanisms for treatment response and pattern of failure. Recent cytogenetic and genomic studies demonstrated influences of select chromosomal regions on outcome to treatment and survival. These included genetic and epigenetic alterations affecting CDKN2A (9p21.3) that distinguished PCNSL from its systemic counterpart. We now report that deletion of 9p21.3/p16 is associated with a negative effect on survival. Methods and Patients. Well-annotated and population-based formalin fixed paraffin embedded (FFPE) patient samples were sourced from the SEER TRP. Specimens were retrieved from the Hawaii, Iowa and Los Angeles County (LA Co) tissue repositories. “Home Brew” fluorescent in situ hybridization (FISH) probes for BCL6, and ptpr-α were prepared according to a standard protocol (Cady et al. J Clin Oncol 2008;26:4814-9). FISH probes for 9p.21 were prepared similarly and then compared to a commercially available probe. Survival was based on the SEER TRP clinical annotations. Results. Thirty five patients were sourced - twelve from Iowa, 13 from Hawaii, and 10 from LA County. The test cohort was 23 from Iowa and Hawaii; the FISH probe failed in 9 and three had insufficient remaining tumor for analysis. For the Iowa and Hawaii registries and for the registries combined the lack of FISH probe detection of 9p.21/p16 correlated with survival (p=0.0159) and was independent of BCL6 (p=0.8788) and ptpr-α (p=0.3724). Conclusion. Deletion of p16 confers a negative effect on survival of PCNSL patients and appears to be independent of treatment, age, BCL6 and ptpr-α status. These results need to be confirmed in a larger sample size. 9p21.3 detection by FISH in feasible in surgical specimens and may aid in the stratification of such patients into different and/or more intensive treatment regimens. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4507. doi:1538-7445.AM2012-4507