Disruption of KLHL6 Fuels Oncogenic Antigen Receptor Signaling in B-cell Lymphoma.

Pathomechanisms that activate oncogenic B-cell receptor (BCR) signaling in diffuse large B-cell lymphoma (DLBCL), are largely unknown. Kelch-like family member 6 (KLHL6) encoding a substrate-adapter for Cullin-3-RING E3 ubiquitin-ligase (CRL) with poorly established targets is recurrently mutated in DLBCL. By applying high-throughput protein interactome screens and functional characterization, we discovered that KLHL6 regulates BCR by targeting its signaling subunits CD79A and CD79B. Loss of physiological KLHL6 expression pattern was frequent among the MCD/C5-like activated B-cell DLBCLs and was associated with higher CD79B levels and dismal outcome. Mutations in the BTB domain of KLHL6 disrupted its localization and heterodimerization, and increased surface BCR levels and signaling, whereas Kelch domain mutants had the opposite effect. Malfunctions of KLHL6 mutants extended beyond proximal BCR signaling with distinct phenotypes from KLHL6 silencing. Collectively, our findings uncover how recurrent mutations in KLHL6 alter BCR signaling and induce actionable phenotypic characteristics in DLBCL.

Inflammatory and subtype-dependent serum protein signatures predict survival beyond the ctDNA in aggressive B cell lymphomas.

BACKGROUND: Biological heterogeneity of large B cell lymphomas (LBCLs) is poorly captured by current prognostic tools, hampering optimal treatment decisions. METHODS: We dissected the levels of 1,463 serum proteins in a uniformly treated trial cohort of 109 patients with high-risk primary LBCL (ClinicalTrials.gov: NCT01325194) and correlated the profiles with molecular data from tumor tissue and circulating tumor DNA (ctDNA) together with clinical data. FINDINGS: We discovered clinically and biologically relevant associations beyond established clinical estimates and ctDNA. We identified an inflamed serum protein profile, which reflected host response to lymphoma, associated with inflamed and exhausted tumor microenvironment features and high ctDNA burden, and translated to poor outcome. We composed an inflammation score based on the identified inflammatory proteins and used the score to predict survival in an independent LBCL trial cohort (ClinicalTrials.gov: NCT03293173). Furthermore, joint analyses with ctDNA uncovered multiple serum proteins that correlate with tumor burden. We found that SERPINA9, TACI, and TARC complement minimally invasive subtype profiling and that TACI and TARC can be used to evaluate treatment response in a subtype-dependent manner in the liquid biopsy. CONCLUSIONS: Altogether, we discovered distinct serum protein landscapes that dissect the heterogeneity of LBCLs and provide agile, minimally invasive tools for precision oncology. FUNDING: This research was funded by grants from the Research Council of Finland, Finnish Cancer Organizations, Sigrid Juselius Foundation, University of Helsinki, iCAN Digital Precision Cancer Medicine Flagship, Orion Research Foundation sr, and Helsinki University Hospital.

Clinical Impact of Immune Cells and Their Spatial Interactions in Diffuse Large B-Cell Lymphoma Microenvironment.

PURPOSE: Tumor-infiltrating immune cells have prognostic significance and are attractive therapeutic targets. Yet, the clinical significance of their spatial organization and phenotype in diffuse large B-cell lymphoma (DLBCL) is unclear. EXPERIMENTAL DESIGN: We characterized T cells, macrophages, and their spatial interactions by multiplex IHC (mIHC) in 178 patients with DLBCL and correlated the data with patient demographics and survival. We validated the findings on gene expression data from two external DLBCL cohorts comprising 633 patients. RESULTS: Macrophage and T-cell contents divided the samples into T cell-inflamed (60%) and noninflamed (40%) subgroups. The T cell-inflamed lymphoma microenvironment (LME) was also rich in other immune cells, defining immune hot phenotype, which did not as such correlate with outcome. However, when we divided the patients according to T-cell and macrophage contents, LME characterized by high T-cell/low macrophage content or a corresponding gene signature was associated with superior survival [5-year overall survival (OS): 92.3% vs. 74.4%, P = 0.036; 5-year progression-free survival (PFS): 92.6% vs. 69.8%, P = 0.012]. High proportion of PD-L1- and TIM3-expressing CD163- macrophages in the T cell-inflamed LME defined a group of patients with poor outcome [OS: HR = 3.22, 95% confidence interval (CI), 1.63-6.37, Padj = 0.011; PFS: HR = 2.76, 95% CI, 1.44-5.28, Padj = 0.016]. Furthermore, PD-L1 and PD-1 were enriched on macrophages interacting with T cells. CONCLUSIONS: Our data demonstrate that the interplay between macrophages and T cells in the DLBCL LME is immune checkpoint dependent and clinically meaningful.

Checkpoint protein expression in the tumor microenvironment defines the outcome of classical Hodgkin lymphoma patients.

Emerging evidence indicates a major impact for the tumor microenvironment (TME) and immune escape in the pathogenesis and clinical course of classical Hodgkin lymphoma (cHL). We used gene expression profiling (n = 88), CIBERSORT, and multiplex immunohistochemistry (n = 131) to characterize the immunoprofile of cHL TME and correlated the findings with survival. Gene expression analysis divided tumors into subgroups with T cell-inflamed and -noninflamed TME. Several macrophage-related genes were upregulated in samples with the non-T cell-inflamed TME, and based on the immune cell proportions, the samples clustered according to the content of T cells and macrophages. A cluster with high proportions of checkpoint protein (programmed cell death protein 1, PD-1 ligands, indoleamine 2,3 dioxygenase 1, lymphocyte-activation gene 3, and T-cell immunoglobulin and mucin domain containing protein 3) positive immune cells translated to unfavorable overall survival (OS) (5-year OS 76% vs 96%; P = .010) and remained an independent prognostic factor for OS in multivariable analysis (HR, 4.34; 95% CI, 1.05-17.91; P = .043). cHL samples with high proportions of checkpoint proteins overexpressed genes coding for cytolytic factors, proposing paradoxically that they were immunologically active. This checkpoint molecule gene signature translated to inferior survival in a validation cohort of 290 diagnostic cHL samples (P < .001) and in an expansion cohort of 84 cHL relapse samples (P = .048). Our findings demonstrate the impact of T cell- and macrophage-mediated checkpoint system on the survival of patients with cHL.

Molecular features encoded in the ctDNA reveal heterogeneity and predict outcome in high-risk aggressive B-cell lymphoma.

Inadequate molecular and clinical stratification of the patients with high-risk diffuse large B-cell lymphoma (DLBCL) is a clinical challenge hampering the establishment of personalized therapeutic options. We studied the translational significance of liquid biopsy in a uniformly treated trial cohort. Pretreatment circulating tumor DNA (ctDNA) revealed hidden clinical and biological heterogeneity, and high ctDNA burden determined increased risk of relapse and death independently of conventional risk factors. Genomic dissection of pretreatment ctDNA revealed translationally relevant phenotypic, molecular, and prognostic information that extended beyond diagnostic tissue biopsies. During therapy, chemorefractory lymphomas exhibited diverging ctDNA kinetics, whereas end-of-therapy negativity for minimal residual disease (MRD) characterized cured patients and resolved clinical enigmas, including false residual PET positivity. Furthermore, we discovered fragmentation disparities in the cell-free DNA that characterize lymphoma-derived ctDNA and, as a proof-of-concept for their clinical application, used machine learning to show that end-of-therapy fragmentation patterns predict outcome. Altogether, we have discovered novel molecular determinants in the liquid biopsy that can noninvasively guide treatment decisions.

Immune cell constitution in the tumor microenvironment predicts the outcome in diffuse large B-cell lymphoma.

The tumor microenvironment (TME) and limited immune surveillance play important roles in lymphoma pathogenesis. Here we aimed to characterize immunological profiles of diffuse large B-cell lymphoma (DLBCL) and predict the outcome in response to immunochemotherapy. We profiled the expression of 730 immune-related genes in tumor tissues of 81 patients with DLBCL utilizing the Nanostring platform, and used multiplex immunohistochemistry to characterize T-cell phenotypes, including cytotoxic T cells (CD8, Granzyme B, OX40, Ki67), T-cell immune checkpoint (CD3, CD4, CD8, PD1, TIM3, LAG3), as well as regulatory T-cells and Th1 effector cells (CD3, CD4, FOXP3, TBET) in 188 patients. We observed a high degree of heterogeneity at the transcriptome level. Correlation matrix analysis identified gene expression signatures with highly correlating genes, the main cluster containing genes for cytolytic factors, immune checkpoint molecules, T cells and macrophages, together named a TME immune cell signature. Immunophenotyping of the distinct cell subsets revealed that a high proportion of immune checkpoint positive T cells translated to unfavorable survival. Together, our results demonstrate that the immunological profile of DLBCL TME is heterogeneous and clinically meaningful. This highlights the potential impact of T-cell immune checkpoint in regulating survival and resistance to immunochemotherapy. (Registered at clinicaltrials.gov identifiers: NCT01502982 and NCT01325194.)

Molecular background delineates outcome of double protein expressor diffuse large B-cell lymphoma.

Concomitant deregulation of MYC and BCL2 comprises clinically significant, yet poorly characterized biological high-risk feature in diffuse large B-cell lymphoma (DLBCL). To interrogate these lymphomas, we analyzed translocations and protein expression of BCL2, BCL6, and MYC; correlated the findings with comprehensive mutational, transcriptomic, and clinical data in 181 patients with primary DLBCL; and validated the key findings in independent data sets. Structural variations of BCL2 were subtype-specific and specifically increased BCL2 expression. Molecular dissection of MYC deregulation revealed associations with other lymphoma drivers, including loss of TP53, and distinctive gene expression profiles. Double protein expression (DPE) arose from heterogeneous molecular backgrounds that exhibited subtype-dependent patterns. In the germinal center B-cell (GCB) DLBCL, concurrent alterations of MYC and BCL2 loci gave rise to the majority of DPE DLBCLs, whereas among the activated B-cell (ABC) DLBCLs, concurrent alterations were infrequent. Clinically, DPE DLBCL defined a prognostic entity, which was independent of the International Prognostic Index (IPI) and cell of origin, and together with the loss of TP53 had a synergistic dismal impact on survival. In the DPE DLBCL, the loss of TP53 was associated with a chemorefractory disease, whereas among the other DLBCLs, no correlation with survival was seen. Importantly, BCL6 translocations identified non-GCB lymphomas with favorable BN2/C1-like survival independent of IPI and concurrent DPE status. Taken together, our findings define molecular characteristics of the DPE in DLBCL, and recognize clinically feasible predictors of outcome. Given the emerging taxonomical significance of BCL2, BCL6, MYC, and TP53, our findings provide further depth and validation to the genomic classification of DLBCL.

Adverse prognostic impact of regulatory T-cells in testicular diffuse large B-cell lymphoma.

OBJECTIVES: Testicular diffuse large B-cell lymphoma (T-DLBCL) is a rare and aggressive extranodal lymphoma. We have previously shown that high content of tumor-infiltrating lymphocytes (TILs) and PD-1 expressing TILs associate with better survival in T-DLBCL. In this study, we have further characterized distinct TIL subtypes and their proportions in association with patient demographics and survival. METHODS: We used multiplex immunohistochemistry to characterize TIL phenotypes, including cytotoxic T-cells (CTLs; CD8+ , OX40+ , Granzyme B+ , Ki-67+ , LAG-3+ , TIM-3+ , PD-1+ ), CD4+ T-cells (CD3+ , CD4+ , TIM-3+ , LAG-3+ ), regulatory T-cells (Tregs; CD3+ , CD4+ , FoxP3+ ), and T helper 1 cells (Th1; CD3+ , CD4+ , T-bet+ ) in 79 T-DLBCLs, and correlated the findings with patient demographics and outcome. RESULTS: We observed a substantial variation in TIL phenotypes between the patients. The most prominent CD8+ TILs were Ki-67+ and TIM-3+ CTLs, whereas the most prominent CD4+ TILs were FoxP3+ Tregs. Despite the overall favorable prognostic impact of high TIL content, we found a subpopulation of T-bet+ FoxP3+ Tregs that had a significant adverse impact on survival. Lower content of CTLs with activated or exhausted phenotypes correlated with aggressive clinical features. CONCLUSIONS: Our results demonstrate significant variation in TIL phenotypes and emphasize the adverse prognostic impact of Tregs in T-DLBCL.

Patients with high-risk DLBCL benefit from dose-dense immunochemotherapy combined with early systemic CNS prophylaxis.

Survival of patients with high-risk diffuse large B-cell lymphoma (DLBCL) is suboptimal, and the risk of central nervous system (CNS) progression is relatively high. We conducted a phase 2 trial in 139 patients aged 18 to 64 years who had primary DLBCL with an age-adjusted International Prognostic Index (aaIPI) score of 2 to 3 or site-specific risk factors for CNS recurrence. The goal was to assess whether a dose-dense immunochemotherapy with early systemic CNS prophylaxis improves the outcome and reduces the incidence of CNS events. Treatment consisted of 2 courses of high-dose methotrexate in combination with biweekly rituximab (R), cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP-14), followed by 4 courses of R-CHOP-14 with etoposide (R-CHOEP) and 1 course of high-dose cytarabine with R. In addition, liposomal cytarabine was administered intrathecally at courses 1, 3, and 5. Coprimary endpoints were failure-free survival and CNS progression rates. Thirty-six (26%) patients experienced treatment failure. Progression occurred in 23 (16%) patients, including three (2.2%) CNS events. At 5 years of median follow-up, failure-free survival, overall survival, and CNS progression rates were 74%, 83%, and 2.3%, respectively. Treatment reduced the risk of progression compared with our previous trial, in which systemic CNS prophylaxis was given after 6 courses of biweekly R-CHOEP (hazard ratio, 0.49; 95% CI, 0.31-0.77; P = .002) and overcame the adverse impact of an aaIPI score of 3 on survival. In addition, outcome of the patients with BCL2/MYC double-hit lymphomas was comparable to the patients without the rearrangements. The results are encouraging, with a low toxic death rate, low number of CNS events, and favorable survival rates. This trial was registered at www.clinicaltrials.gov as #NCT01325194.

Prognostic Impact of Tumor-Associated Macrophages on Survival Is Checkpoint Dependent in Classical Hodgkin Lymphoma.

Tumor microenvironment and immune escape affect pathogenesis and survival in classical Hodgkin lymphoma (cHL). While tumor-associated macrophage (TAM) content has been associated with poor outcomes, macrophage-derived determinants with clinical impact have remained undefined. Here, we have used multiplex immunohistochemistry and digital image analysis to characterize TAM immunophenotypes with regard to expression of checkpoint molecules programmed cell death ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1) from the diagnostic tumor tissue samples of 130 cHL patients, and correlated the findings with clinical characteristics and survival. We show that a large proportion of TAMs express PD-L1 (CD68+, median 32%; M2 type CD163+, median 22%), whereas the proportion of TAMs expressing IDO-1 is lower (CD68+, median 5.5%; CD163+, median 1.4%). A high proportion of PD-L1 and IDO-1 expressing TAMs from all TAMs (CD68+), or from CD163+ TAMs, is associated with inferior outcome. In multivariate analysis with age and stage, high proportions of PD-L1+ and IDO-1+ TAMs remain independent prognostic factors for freedom from treatment failure (PD-L1+CD68+/CD68+, HR = 2.63, 95% CI 1.17-5.88, p = 0.019; IDO-1+CD68+/CD68+, HR = 2.48, 95% CI 1.03-5.95, p = 0.042). In contrast, proportions of PD-L1+ tumor cells, all TAMs or PD-L1- and IDO-1- TAMs are not associated with outcome. The findings implicate that adverse prognostic impact of TAMs is checkpoint-dependent in cHL.

Prognostic implications of the microenvironment for follicular lymphoma under immunomodulation therapy.

Follicular lymphoma (FL) constitutes a significant proportion of lymphomas and shows frequent relapses. Beyond conventional chemotherapy, new therapeutic approaches have emerged, focussing on the interplay between lymphoma cells and the microenvironment. Here we report the immunophenotypic investigation of the microenvironment of a clinically well-characterized prospective cohort (study SAKK35/10, NCT01307605) of 154 treatment-naïve FL patients in need of therapy, who have been treated with rituximab only or a combination of rituximab and the immunomodulatory drug lenalidomide/Revlimid® A high ratio of CD4- to CD8-positive T cells (P = 0·009) and increased amounts of PD1+ tumour-infiltrating T cells (P = 0·007) were associated with inferior progression-free survival in the whole cohort. Interestingly, the prognostic impact of PD1+ T cells and the CD4/CD8 ratio lost its significance in the subgroup treated with R2 . In the latter group, high amounts of GATA3+ T helper (Th2) equivalents were associated with better progression-free survival (P < 0·001). We identified tumour microenvironmental features that allow prognostic stratification with respect to immuno- and combined immuno- and immunomodulatory therapy. Our analysis indicates that lenalidomide may compensate the adverse prognostic implication of higher amounts of CD4+ and, particularly, PD1+ T cells and that it has favourable effects mainly in cases with higher amounts of Th2 equivalents. [Correction added on 11 February 2020, after online publication: The NCT-trial number was previously incorrect and has been updated in this version].

Clinical features and outcome of the patients with sinonasal tract diffuse large B-cell lymphoma in the pre-rituximab and rituximab eras.

PURPOSE: Sinonasal tract diffuse large B-cell lymphoma (SNT-DLBCL), a rare extranodal lymphoma, is not well characterized. We performed a population-based study to determine cell-of-origin, clinical presentation and impact of rituximab (R) and central nervous system (CNS) directed chemotherapy on survival. PATIENTS AND METHODS: Patients with SNT-DLBCL were identified from pathology databases. Clinical information was collected and outcomes between different treatment modalities evaluated. RESULTS: Thirty-two percent of the patients had germinal centre B-cell phenotype. Forty-six patients were treated with curative intent using CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) or CHOP-like chemotherapy, 21 (46%) before and 25 (54%) in the R-era. Additionally, 24 (52%) received CNS-directed chemotherapy. Addition of R to chemotherapy reduced the risk of progression (RR = 0.368, 95% CI 0.138-0.976, P = 0.045) and death (RR = 0.245, 95% CI 0.068-0.883, P = 0.032), and translated into better survival (5-year PFS, 67% vs 38%, P = 0.037; 5-year OS, 81% vs 48%, P = 0.020). CNS-directed chemotherapy reduced the risk of progression (RR = 0.404, 95% CI 0.159-1.029, P = 0.057) and death (RR = 0.298, 95% CI 0.093-0.950, P = 0.041), and translated into favorable survival (5-year PFS, 67% vs 32%, P = 0.050; 5-year OS 82% vs 43%, P = 0.030). CONCLUSION: Patients with SNT-DLBCL benefit from rituximab and CNS-directed chemotherapy.

T-cell inflamed tumor microenvironment predicts favorable prognosis in primary testicular lymphoma.

Primary testicular lymphoma is a rare lymphoid malignancy, most often, histologically, representing diffuse large B-cell lymphoma. The tumor microenvironment and limited immune surveillance have a major impact on diffuse large B-cell lymphoma pathogenesis and survival, but the impact on primary testicular lymphoma is unknown. Here, the purpose of the study was to characterize the tumor microenvironment in primary testicular lymphoma, and associate the findings with outcome. We profiled the expression of 730 immune response genes in 60 primary testicular lymphomas utilizing the Nanostring platform, and used multiplex immunohistochemistry to characterize the immune cell phenotypes in the tumor tissue. We identified a gene signature enriched for T-lymphocyte markers differentially expressed between the patients. Low expression of the signature predicted poor outcome independently of the International Prognostic Index (progression-free survival: HR=2.810, 95%CI: 1.228-6.431, P=0.014; overall survival: HR=3.267, 95%CI: 1.406-7.590, P=0.006). The T-lymphocyte signature was associated with outcome also in an independent diffuse large B-cell lymphoma cohort (n=96). Multiplex immunohistochemistry revealed that poor survival of primary testicular lymphoma patients correlated with low percentage of CD3+CD4+ and CD3+CD8+ tumor-infiltrating lymphocytes (P<0.001). Importantly, patients with a high T-cell inflamed tumor microenvironment had a better response to rituximab-based immunochemotherapy, as compared to other patients. Furthermore, loss of membrane-associated human-leukocyte antigen complexes was frequent and correlated with low T-cell infiltration. Our results demonstrate that a T-cell inflamed tumor microenvironment associates with favorable survival in primary testicular lymphoma. This further highlights the importance of immune escape as a mechanism of treatment failure.

PD-L1+ tumor-associated macrophages and PD-1+ tumor-infiltrating lymphocytes predict survival in primary testicular lymphoma.

Primary testicular lymphoma is a rare and aggressive lymphoid malignancy, most often representing diffuse large B-cell lymphoma histologically. Tumor-associated macrophages and tumor-infiltrating lymphocytes have been associated with survival in diffuse large B-cell lymphoma, but their prognostic impact in primary testicular lymphoma is unknown. Here, we aimed to identify macrophages, their immunophenotypes and association with lymphocytes, and translate the findings into survival of patients with primary testicular lymphoma. We collected clinical data and tumor tissue from 74 primary testicular lymphoma patients, and used multiplex immunohistochemistry and digital image analysis to examine macrophage markers (CD68, CD163, and c-Maf), T-cell markers (CD3, CD4, and CD8), B-cell marker (CD20), and three checkpoint molecules (PD-L1, PD-L2, and PD-1). We demonstrate that a large proportion of macrophages (median 41%, range 0.08-99%) and lymphoma cells (median 34%, range 0.1-100%) express PD-L1. The quantity of PD-L1+ CD68+ macrophages correlates positively with the amount of PD-1+ lymphocytes, and a high proportion of either PD-L1+ CD68+ macrophages or PD-1+ CD4+ and PD-1+ CD8+ T cells translates into favorable survival. In contrast, the number of PD-L1+lymphoma cells or PD-L1- macrophages do not associate with outcome. In multivariate analyses with IPI, PD-L1+ CD68+ macrophage and PD-1+ lymphocyte contents remain as independent prognostic factors for survival. In conclusion, high PD-L1+ CD68+ macrophage and PD-1+ lymphocyte contents predict favorable survival in patients with primary testicular lymphoma. The findings implicate that the tumor microenvironment and PD-1 - PD-L1 pathway have a significant role in regulating treatment outcome. They also bring new insights to the targeted thera py of primary testicular lymphoma.

MicroRNAs regulate key cell survival pathways and mediate chemosensitivity during progression of diffuse large B-cell lymphoma.

Despite better therapeutic options and improved survival of diffuse large B-cell lymphoma (DLBCL), 30-40% of the patients experience relapse or have primary refractory disease with a dismal prognosis. To identify biological correlates for treatment resistance, we profiled microRNAs (miRNAs) of matched primary and relapsed DLBCL by next-generation sequencing. Altogether 492 miRNAs were expressed in the DLBCL samples. Thirteen miRNAs showed significant differential expression between primary and relapse specimen pairs. Integration of the differentially expressed miRNAs with matched mRNA expression profiles identified highly anti-correlated, putative targets, which were significantly enriched in cancer-associated pathways, including phosphatidylinositol (PI)), mitogen-activated protein kinase (MAPK), and B-cell receptor (BCR) signaling. Expression data suggested activation of these pathways during disease progression, and functional analyses validated that miR-370-3p, miR-381-3p, and miR-409-3p downregulate genes on the PI, MAPK, and BCR signaling pathways, and enhance chemosensitivity of DLBCL cells in vitro. High expression of selected target genes, that is, PIP5K1 and IMPA1, was found to be associated with poor survival in two independent cohorts of chemoimmunotherapy-treated patients (n = 92 and n = 233). Taken together, our results demonstrate that differentially expressed miRNAs contribute to disease progression by regulating key cell survival pathways and by mediating chemosensitivity, thus representing potential novel therapeutic targets.

Genetic and Functional Drivers of Diffuse Large B Cell Lymphoma.

Diffuse large B cell lymphoma (DLBCL) is the most common form of blood cancer and is characterized by a striking degree of genetic and clinical heterogeneity. This heterogeneity poses a major barrier to understanding the genetic basis of the disease and its response to therapy. Here, we performed an integrative analysis of whole-exome sequencing and transcriptome sequencing in a cohort of 1,001 DLBCL patients to comprehensively define the landscape of 150 genetic drivers of the disease. We characterized the functional impact of these genes using an unbiased CRISPR screen of DLBCL cell lines to define oncogenes that promote cell growth. A prognostic model comprising these genetic alterations outperformed current established methods: cell of origin, the International Prognostic Index comprising clinical variables, and dual MYC and BCL2 expression. These results comprehensively define the genetic drivers and their functional roles in DLBCL to identify new therapeutic opportunities in the disease.

Clinical findings in 25 patients with sinonasal or nasopharyngeal extramedullary plasmacytoma in a four-decade single-centre series.

OBJECTIVES: Extramedullary plasmacytoma in the sinonasal tract or nasopharynx is rare. The aim of the study was to review data on symptoms, clinical findings, treatment and follow-up of plasmacytomas in the sinonasal and nasopharyngeal regions in order to delineate the main clinical characteristics and the optimal management. METHOD: Twenty-five patients with sinonasal or nasopharyngeal plasmacytoma, diagnosed and treated at the Helsinki University Hospital during a 39-year period from 1975 to 2013 were retrospectively reviewed. RESULTS: There were 18 males and 7 females with a median age of 66 years (range, 36-80). Sixty-eight percent received only radiotherapy or (chemo)radiotherapy. Forty-seven percent of them had a complete response to primary radiotherapy and one patient had a complete response after receiving additional brachytherapy. Four patients were treated primarily with surgery only. Two of them had a local recurrence, but were then successfully treated with radiotherapy. Altogether, four patients received a combination of surgery and (chemo)radiotherapy. Forty-four percent were alive with no evidence of disease after a median follow-up time of 78 months. Forty percent died of their disease and 16% died of other causes. CONCLUSIONS: Our study supports radiotherapy as a treatment of choice, but for small tumours surgery alone or in combination with radiotherapy may also be considered.