Sergei Syrbu

Rates and Outcomes of Follicular Lymphoma Transformation in the Immunochemotherapy Era: A Report From the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource

PURPOSE This study sought to characterize transformation incidence and outcome for patients with follicular lymphoma (FL) in a prospective observational series begun after diffusion of rituximab use. PATIENTS AND METHODS Patients with newly diagnosed FL were prospectively enrolled onto the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource from 2002 to 2009. Patients were actively followed for re-treatment, clinical or pathologic transformation, and death. Risk of transformation was analyzed via time to transformation by using death as a competing risk. RESULTS In all, there were 631 patients with newly diagnosed grade 1 to 3a FL who had a median age at enrollment of 60 years. At a median follow-up of 60 months (range, 11 to 110 months), 79 patients had died, and 60 patients developed transformed lymphoma, of which 51 were biopsy proven. The overall transformation rate at 5 years was 10.7%, with an estimated rate of 2% per year. Increased lactate dehydrogenase was associated with increased risk of transformation. Transformation rate at 5 years was highest in patients who were initially observed and lowest in patients who initially received rituximab monotherapy (14.4% v 3.2%; P = .021). Median overall survival following transformation was 50 months and was superior in patients with transformation greater than 18 months after FL diagnosis compared with patients with earlier transformation (5-year overall survival, 66% v 22%; P < .001). CONCLUSION Follicular transformation rates in the immunochemotherapy era are similar to risk of death without transformation and may be lower than reported in older series. Post-transformation prognosis is substantially better than described in older series. Initial management strategies may influence the risk of transformation.

Elevated Serum Free Light Chains Are Associated With Event-Free and Overall Survival in Two Independent Cohorts of Patients With Diffuse Large B-Cell Lymphoma

PURPOSE The serum free light chain (FLC) assay quantitates free kappa (κ) and free lambda (λ) immunoglobulin light chains. This assay has prognostic value in plasma cell proliferative disorders. There are limited data on serum FLC in B-cell malignancies. PATIENTS AND METHODS The association of pretreatment FLC with event-free survival (EFS) and overall survival (OS) in diffuse large B-cell lymphoma (DLBCL) was evaluated in 76 patients from the North Central Cancer Treatment Group trial N0489 (NCT00301821) and 219 patients from the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource (MER). Published reference ranges were used to define an elevated FLC or an abnormal κ:λ FLC ratio. RESULTS Elevated FLC or abnormal κ:λ FLC ratio was present in 32% and 14% of patients, respectively. Patients with elevated FLC had an inferior OS and EFS in both cohorts compared with patients with normal FLC (N0489: EFS hazard ratio [HR], 3.06; OS HR, 3.16; both P < .02; MER: EFS HR, 2.42; OS HR, 3.40; both P < .001; combined EFS HR, 2.57; OS HR, 3.74; both P < .001). All associations remained significant for EFS and OS after adjusting for the International Prognostic Index (IPI). Abnormal κ:λ FLC ratio was modestly associated with outcome in the combined group (EFS HR, 1.61; OS HR, 1.67; both P = .07), but not in patients without corresponding elevated κ or λ. Elevated FLC was the strongest predictor of outcome in multivariable models with the IPI components. CONCLUSION Increased serum FLC is an independent, adverse prognostic factor for EFS and OS in DLBCL and warrants further evaluation as a biomarker in DLBCL.

Expression profiling of transcription factors Pax-5, Oct-1, Oct-2, BOB.1, and PU.1 in Hodgkin's and non-Hodgkin's lymphomas: a comparative study using high throughput tissue microarrays

Analysis of B-cell-specific transcription factors is useful in understanding of the differentiation-linked phenotype in Hodgkins as well as in non-Hodgkins lymphomas. We analyzed the expression profiling of transcription factors Pax-5, Oct-1, Oct-2, BOB.1, and PU.1 in 109 cases, including non-Hodgkins lymphomas of B- and T-lineage, classical Hodgkins lymphomas, and nodular lymphocyte predominant Hodgkins lymphomas. Our study revealed that all transcription factors were universally expressed in all cases of nodular lymphocyte predominant Hodgkins and variably expressed in non-Hodgkins lymphomas of B-lineage. Cases of classical Hodgkins lymphoma variably expressed the Pax-5, Oct-1, Oct-2, and BOB.1. However, in contrast to nodular lymphocyte predominant Hodgkins lymphoma, the transcription factor PU.1 was consistently absent in all cases of classical Hodgkins lymphoma. Transcription factors Pax-5, BOB.1, and PU.1 were not detectable in cases of anaplastic large cell lymphoma. However, the Oct-1 was detected in all anaplastic large cells lymphoma cases, indicating that expression of this transcription factor was not restricted to B-lineage lymphoid malignancies. Our findings suggest that inclusion of the PU.1 antibody may prove useful in separating classical Hodgkins lymphomas from nodular lymphocyte predominant Hodgkins lymphomas in problematic cases.

Early event status informs subsequent outcome in newly diagnosed follicular lymphoma

Recent advances in follicular lymphoma (FL) have resulted in prolongation of overall survival (OS). Here we assessed if early events as defined by event‐free survival (EFS) at 12 and 24 months from diagnosis (EFS12/EFS24) can inform subsequent OS in FL. 920 newly diagnosed grade 1‐3A FL patients enrolled on the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER) from 2002‐2012 were initially evaluated. EFS was defined as time from diagnosis to progression, relapse, re‐treatment, or death due to any cause. OS was compared to age‐and‐sex‐matched survival in the general US population using standardized mortality ratios (SMR) and 95% confidence intervals (CI). We used a cohort of 412 FL patients from two Lyon, France hospital registries for independent replication. Patients who failed to achieve EFS12 had poor subsequent OS (MER SMR = 3.72, 95%CI: 2.78‐4.88; Lyon SMR = 8.74, 95%CI: 5.41‐13.36). Conversely, patients achieving EFS12 had no added mortality beyond the background population (MER SMR = 0.73, 95%CI: 0.56‐0.94, Lyon SMR = 1.02, 95%CI: 0.58‐1.65). Patients with early events after immunochemotherapy had especially poor outcomes (EFS12 failure: MER SMR = 17.63, 95%CI:11.97‐25.02, Lyon SMR = 19.10, 95%CI:9.86‐33.36; EFS24 failure: MER SMR = 13.02, 95%CI:9.31‐17.74, Lyon SMR = 7.22, 95%CI:4.13‐11.74). In a combined dataset of all patients from both cohorts, baseline FLIPI was no longer informative in EFS12 achievers. Reassessment of patient status at 12 months from diagnosis in follicular lymphoma patients, or at 24 months in patients treated with immunochemotherapy, is a strong predictor of subsequent overall survival in FL. Early event status provides a simple, clinically relevant endpoint for studies assessing outcome in FL. Am. J. Hematol. 91:1096–1101, 2016.

An enhanced antigen-retrieval protocol for immunohistochemical staining of formalin-fixed, paraffin-embedded tissues.

Formalin is the most commonly used fixative for light microscopy because of its preservation of -morphological details. A major adverse effect of formalin fixation is formation of cross-linkages between epitopes (amino acid residues) and unrelated proteins by formaldehyde groups. The great majority of monoclonal and polyclonal antibodies used for immunohistochemical (IHC) staining of formalin-fixed, paraffin-embedded (FFPE) tissues necessitate unmasking antigens for antigen retrieval. There are currently two major antigen-retrieval procedures based on treatment of deparaffinized tissue sections with heat or, less commonly, with enzymatic digestion. The use of various antigen-retrieval solutions and heating sources does not allow standardization of IHC staining and minimalization of interlaboratory discrepancies. We developed a novel modified antigen-retrieval protocol for reversing the effect of -formalin fixation. The key feature of this protocol is treatment of deparaffinized tissue sections at reduced constant heat (97(o)C in a water bath) for 40 min in 25 mM Tris-HCl (pH 8.5), 1 mM EDTA, and 0.05% SDS (Tris-EDTA-SDS) buffer. Sections are then immunostained with primary and secondary antibodies conjugated with polymer-labeled Horse Radish Peroxidase. Compared to conventional antigen-retrieval procedures, this protocol more efficiently reverses the effect of formalin fixation of a wide variety of cellular antigens and in most instances decreases the use of primary antibody by 2-40 times, resulting in cost savings. Moreover, this protocol eliminates the need for using different antigen-retrieval methods in the laboratory, which reduces both time and labor for medical technologists.

TRAIL-DISC Formation Is Androgen-Dependent in the Human Prostatic Carcinoma Cell Line LNCaP

We and others have previously described that the androgen-responsive human prostatic carcinoma cell line LNCaP is resistant to TRAIL and that TRAIL-mediated apoptosis in LNCaP is PI3K/Akt-dependent. In this study, we found that LNCaP remained resistant to treatment with TRAIL after androgen deprivation even in the presence of the PI3K/Akt pathway inhibitor wortmannin. This resistance was determined by failure to form the TRAIL-DISC and by decreased TRAIL-R1 and TRAIL-R2 levels after androgen deprivation; the capacity of TRAIL to induce DISC formation was completely restored in the presence of DHT. TRAIL and wortmannin together accelerated processing of caspase-8 on the DISC and apparently the release of caspase-8 from the DISC into the cytoplasm. Surprisingly, we found that wortmannin decreased the total amount of TRAIL-R1, but not TRAIL-R2, in the cells as well as the amount of TRAIL-R1 precipitated by TRAIL. Our data suggest that TRAIL-DISC formation and sensitivity to TRAIL treatment are androgen-dependent in LNCaP.

Identification of Candidate B-Lymphoma Genes by Cross- Species Gene Expression Profiling

Comparative genome-wide expression profiling of malignant tumor counterparts across the human-mouse species barrier has a successful track record as a gene discovery tool in liver, breast, lung, prostate and other cancers, but has been largely neglected in studies on neoplasms of mature B-lymphocytes such as diffuse large B cell lymphoma (DLBCL) and Burkitt lymphoma (BL). We used global gene expression profiles of DLBCL-like tumors that arose spontaneously in Myc-transgenic C57BL/6 mice as a phylogenetically conserved filter for analyzing the human DLBCL transcriptome. The human and mouse lymphomas were found to have 60 concordantly deregulated genes in common, including 8 genes that Cox hazard regression analysis associated with overall survival in a published landmark dataset of DLBCL. Genetic network analysis of the 60 genes followed by biological validation studies indicate FOXM1 as a candidate DLBCL and BL gene, supporting a number of studies contending that FOXM1 is a therapeutic target in mature B cell tumors. Our findings demonstrate the value of the “mouse filter” for genomic studies of human B-lineage neoplasms for which a vast knowledge base already exists.

Elevated serum levels of IL-2R, IL-1RA and CXCL9 are associated with a poor prognosis in follicular lymphoma

Serum cytokines and chemokines may reflect tumor biology and host response in follicular lymphoma (FL). To determine whether the addition of these biological factors may further refine prognostication, 30 cytokines and chemokines were measured in pretreatment serum specimens from newly diagnosed FL patients (n = 209) and from 400 matched controls. Cytokine levels were correlated with clinical outcome in patients who were observed or received single agent rituximab, or those who received chemotherapy. Correlations with outcome in chemotherapy treated patients were further examined in a separate cohort of 183 South West Oncology Group (SWOG) patients and all patients were then included in a meta-analysis. Six cytokines were associated with outcome in the Molecular Epidemiology Resource (MER) after adjusting for the FL international prognostic index. In patients who were observed or treated with rituximab alone, increased serum IL-12 and interleukin 1 receptor antagonist (IL-1RA) (P = .005 and .02) were associated with a shorter event-free survival. In patients receiving chemotherapy, hepatocyte growth factor, IL-8, IL-1RA, and CXCL9 (P = .015, .048, .004, and .0005) predicted a shorter EFS. When the MER chemotherapy treated patients and SWOG patients were combined in a meta-analysis, IL-2R, IL-1RA, and CXCL9 (P = .013, .042, and .0012) were associated with a poor EFS.

Epstein-Barr virus mimicking lymphoma on FDG-PET/CT.

We report the case of a 17-year-old girl who presented with a several month history of fevers and abdominal pain. After cytomegalovirus (CMV) and Epstein-Barr virus (EBV) titers returned normal, FDG-PET/CT was obtained due to concern for lymphoma. FDG-PET/CT revealed a pattern of hypermetabolic activity in the adenoids, bilateral cervical lymph nodes, abdominal lymph nodes, and spleen, highly concerning for lymphoma. However, subsequent biopsy of a cervical lymph node revealed lymphadenitis consistent with EBV. This case highlights infection as the most well-known false-positive cause on FDG-PET, and how biopsy is essential to definitively distinguish malignancy from infection.

Personalized risk prediction for event-free survival at 24 months in patients with diffuse large B-cell lymphoma.

We recently defined event‐free survival at 24 months (EFS24) as a clinically relevant outcome for patients with DLBCL. Patients who fail EFS24 have very poor overall survival, while those who achieve EFS24 have a subsequent overall survival equivalent to that of the age‐ and sex‐matched general population. Here, we develop and validate a clinical risk calculator (IPI24) for EFS24. Model building was performed on a discovery dataset of 1,348 patients with DLBCL and treated with anthracycline‐based immunochemotherapy. A multivariable model containing age, Ann Arbor stage, normalized serum LDH, ALC, ECOG performance status, bulky disease, and sex was identified. The model was then applied to an independent validation dataset of 1,177 DLBCL patients. The IPI24 score estimates the probability of failing to achieve the EFS24 endpoint for an individual patient. The IPI24 model showed superior discriminatory ability (c‐statistic = 0.671) in the validation dataset compared to the IPI (c‐statistic = 0.649) or the NCCN‐IPI (c‐statistic = 0.657). After recalibration of the model on the combined dataset, the median predicted probability of failing to achieve EFS24 was 36% (range, 12–88%), and the IPI24 showed an EFS24 gradient in all IPI groups. The IPI24 also identified a significant percentage of patients with high risk disease, with over 20% of patients having a 50% or higher risk of failing to achieve EFS24. The IPI24 provides an individual patient level probability of achieving the clinically relevant EFS24 endpoint. It can be used via electronic apps. Am. J. Hematol. 91:179–184, 2016.