MYD88 mutations identify a molecular subgroup of diffuse large B-cell lymphoma with an unfavorable prognosis.

The 2016 World Health Organization classification defines diffuse large B-cell lymphoma (DLBCL) subtypes based on Epstein-Barr virus (EBV) infection and oncogenic rearrangements of MYC/BCL2/BCL6 as drivers of lymphomagenesis. A subset of DLBCL, however, is characterized by activating mutations in MYD88/CD79B We investigated whether MYD88/CD79B mutations could improve the classification and prognostication of DLBCL. In 250 primary DLBCL, MYD88/CD79B mutations were identified by allele-specific polymerase chain reaction or next-generation-sequencing, MYC/BCL2/BCL6 rearrangements were analyzed by fluorescence in situ hybridization, and EBV was studied by EBV-encoded RNA in situ hybridization. Associations of molecular features with clinicopathologic characteristics, outcome, and prognosis according to the International Prognostic Index (IPI) were investigated. MYD88 and CD79B mutations were identified in 29.6% and 12.3%, MYC, BCL2, and BCL6 rearrangements in 10.6%, 13.6%, and 20.3%, and EBV in 11.7% of DLBCL, respectively. Prominent mutual exclusivity between EBV positivity, rearrangements, and MYD88/CD79B mutations established the value of molecular markers for the recognition of biologically distinct DLBCL subtypes. MYD88-mutated DLBCL had a significantly inferior 5-year overall survival than wild-type MYD88 DLBCL (log-rank; P=0.019). DLBCL without any of the studied aberrations had superior overall survival compared to cases carrying ≥1 aberrancy (log-rank; P=0.010). MYD88 mutations retained their adverse prognostic impact upon adjustment for other genetic and clinical variables by multivariable analysis and improved the prognostic performance of the IPI. This study demonstrates the clinical utility of defining MYD88-mutated DLBCL as a distinct molecular subtype with adverse prognosis. Our data call for sequence analysis of MYD88 in routine diagnostics of DLBCL to optimize classification and prognostication, and to guide the development of improved treatment strategies.

Activated neutrophils exert myeloid-derived suppressor cell activity damaging T cells beyond repair.

Myeloid-derived suppressor cells (MDSCs) have the capacity to suppress T-cell-mediated immune responses and impact the clinical outcome of cancer, infections, and transplantation settings. Although MDSCs were initially described as bone marrow-derived immature myeloid cells (either monocytic or granulocytic MDSCs), mature neutrophils have been shown to exert MDSC activity toward T cells in ways that remain unclear. In this study, we demonstrated that human neutrophils from both healthy donors and cancer patients do not exert MDSC activity unless they are activated. By using neutrophils with genetically well-defined defects, we found that reactive oxygen species (ROS) and granule-derived constituents are required for MDSC activity after direct CD11b-dependent interactions between neutrophils and T cells. In addition to these cellular interactions, neutrophils are engaged in the uptake of pieces of T-cell membrane, a process called trogocytosis. Together, these interactions led to changes in T-cell morphology, mitochondrial dysfunction, and adenosine triphosphate depletion, as indicated by electron microscopy, mass spectrometry, and metabolic parameters. Our studies characterize the different steps by which activated mature neutrophils induce functional T-cell nonresponsiveness and irreparable cell damage.

Unknown primary head and neck squamous cell carcinoma in the era of fluorodeoxyglucose-positron emission tomography/CT and intensity-modulated radiotherapy.

BACKGROUND: The diagnosis and treatment of head and neck carcinoma of unknown primary (CUP) have changed with the introduction of fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT and intensity-modulated radiotherapy (IMRT), with potential implications for outcome. METHODS: We conducted a retrospective analysis of 80 patients with head and neck CUP who were PET-staged and treated with curative intention using IMRT between 2006 and 2016 in the Netherlands Cancer Institute. Patient, tumor, and treatment demographics were recorded and oncologic outcomes were analyzed. RESULTS: Local control was 100% in mucosal irradiated patients. Regional control was 90%. Ten patients developed distant metastases, which were associated with N3, extracapsular extension (ECE) and lower neck positive lymph nodes. Overall survival (OS) at 5 years was 62% and disease-specific survival was 78%. ECE, N3 neck, multiple levels of positive lymph nodes, and positive lymph nodes in the lower neck were associated with worse prognosis. CONCLUSION: Locoregional outcome of head and neck CUP managed with modern techniques is good. Future research needs to focus on reducing toxicity and patients prone for distant metastasis.

Treatment of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue with fludarabine: effect on tumor microenvironment.

Gastric Helicobacter pylori (HP) positive extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) develops during chronic antigenic stimulation with specific T-cell help. Chemotherapy that acts both on the malignant B-cells and on T-cells in the microenvironment, i.e. nucleoside analogs, might therefore be an attractive treatment. In 14 patients with gastric MALT lymphoma treated with fludarabine, alterations in T-cell subsets were studied in subsequent peripheral blood samples and in gastric biopsies. Treatment with fludarabine resulted in a steep decrease in T-cell subsets in peripheral blood samples. By contrast no decrease in T-cell populations was observed in subsequent gastric biopsy samples and a moderate increase was observed in relative infiltration with CD3 +, CD4 + and CD8 + cells. In addition an increase in density of FOXP3 + cells (i.e. Tregs) was seen (p = 0.047). These alterations in different T-cell subsets were not observed in gastric biopsy samples of patients treated with HP-eradication only.

Low-dose involved-field radiotherapy as alternative treatment of nodular lymphocyte predominance Hodgkin's lymphoma.

PURPOSE: Nodular lymphocyte predominance Hodgkin's lymphoma is a very rare disease, characterized by an indolent clinical course, with sometimes very late relapses occurring in a minority of all patients. Considerable discussion is ongoing on the treatment of primary and relapsed disease. PATIENTS AND METHODS: A group of 9 patients were irradiated to a dose of 4 Gy on involved areas only. RESULTS: After a median follow-up of 37 months (range, 6-66), the overall response rate was 89%. Six patients had complete remission (67%), two had partial remission (22%), and one had stable disease (11%). Of 8 patients, 5 developed local relapse 9-57 months after radiotherapy. No toxicity was noted. CONCLUSION: In nodular lymphocyte predominance Hodgkin's lymphoma, low-dose radiotherapy provided excellent response rates and lasting remissions without significant toxicity.