Etiologic heterogeneity among non-Hodgkin lymphoma subtypes

Understanding patterns of etiologic commonality and heterogeneity for non-Hodgkin lymphomas may illuminate lymphomagenesis. We present the first systematic comparison of risks by lymphoma subtype for a broad range of putative risk factors in a population-based case-control study, including diffuse large B-cell (DLBCL; N = 416), follicular (N = 318), and marginal zone lymphomas (N = 106), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; N = 133). We required at least 2 of 3 analyses to support differences in risk: (1) polytomous logistic regression, (2) homogeneity tests, or (3) dichotomous logistic regression, analyzing all 7 possible pairwise comparisons among the subtypes, corresponding to various groupings by clinical behavior, genetic features, and differentiation. Late birth order and high body mass index (>/= 35) kg/m(2)) increased risk for DLBCL alone. Autoimmune conditions increased risk for marginal zone lymphoma alone. The tumor necrosis factor G-308A polymorphism (rs1800629) increased risks for both DLBCL and marginal zone lymphoma. Exposure to certain dietary heterocyclic amines from meat consumption increased risk for CLL/SLL alone. We observed no significant risk factors for follicular lymphoma alone. These data clearly support both etiologic commonality and heterogeneity for lymphoma subtypes, suggesting that immune dysfunction is of greater etiologic importance for DLBCL and marginal zone lymphoma than for CLL/SLL and follicular lymphoma.

Nasopharyngeal carcinoma, with emphasis on its relationship to Epstein-Barr virus

Nasopharyngeal carcinoma (NPC) is an epithelial tumor with a distinct geographic distribution and characteristic histologic appearance. It is rare in Europe and North America, but it is among the most common cancers in southern China. Genetic predisposition, environmental factors, and Epstein-Barr virus (EBV) all have been associated with the pathogenesis of this tumor. There is an increasing body of evidence that among all these factors, EBV appears to be the strongest and most consistently related factor. According to the current sensitive in situ hybridization methods for the detection of EBV-encoded small RNAs (EBER), almost 100% of cases of NPC, irrespective of their histologic subtypes, have demonstrable EBERs in the nuclei of the tumor cells. In this review paper, we discuss the predisposing genetic and environmental factors and the role of EBV in the pathogenesis of this tumor with particular emphasis on the role of EBV.

Cyclin D1 immunohistochemical staining is useful in distinguishing mantle cell lymphoma from other low-grade B-cell neoplasms in bone marrow

The distinction between mantle cell lymphoma (MCL) and other low-grade B-cell neoplasms is important because MCL has a more aggressive clinical course. In bone marrow biopsy specimens, this distinction can be especially difficult. We examined 70 bone marrow biopsy specimens involved by various B-cell lymphoid neoplasms to assess the utility of cyclin D1 immunostaining in distinguishing MCL from other B-cell lymphoproliferative disorders. We used a cocktail of two monoclonal anti-cyclin D1 antibodies and a heat- and sonication-induced epitope retrieval procedure. The neoplasms assessed included MCL (32 cases), small lymphocytic lymphoma/chronic lymphocytic leukemia (18 cases), follicular lymphoma (11 cases), hairy cell leukemia (5 cases), splenic marginal zone lymphoma (2 cases), and small lymphocytic lymphoma with plasmacytoid differentiation (2 cases). The diagnosis of MCL in bone marrow was confirmed by review of the original diagnostic biopsy specimens along with additional data, such as immunophenotypic or molecular studies. Most MCL (23/32; 72%) cases expressed cyclin D1 protein. In contrast, one case of small lymphocytic lymphoma/chronic lymphocytic leukemia (1/18; 6%) and one case of hairy cell leukemia (1/5; 20%) expressed cyclin D1 protein. These findings demonstrate that immunostaining for cyclin D1 protein expression is useful in distinguishing MCL from other B-cell lymphoid neoplasms in the bone marrow.

Plasmablastic lymphoma of the lung: report of a unique case and review of the literature

Non-Hodgkin lymphomas associated with acquired immunodeficiency syndrome are heterogeneous. Recently, a novel subtype of non-Hodgkin lymphoma occurring mostly in patients with acquired immunodeficiency syndrome has been described and designated as plasmablastic lymphoma. The histomorphologic and immunophenotypic findings of this distinct subtype of non-Hodgkin lymphoma have been characterized previously. Most patients present with oral cavity involvement. We report a case of plasmablastic lymphoma presenting as a lung tumor. To our knowledge, this is the first case report of this unusual subtype of diffuse large B-cell lymphoma in this location.

Dendritic cell tumors associated with low-grade B-cell malignancies. Report of three cases

Indeterminate and interdigitating cell tumors are rare proliferations of immunoregulatory cells that demonstrate morphologic, immunologic, and ultrastructural features similar to their cells of origin. Although an association of lymphoproliferative disease with Langerhans' cell histiocytosis is well described, only sporadic cases of non-Langerhans' dendritic cell proliferations have been published. The authors describe three patients with low grade B-cell lymphoproliferative disease who developed subsequent indeterminate cell or interdigitating cell tumors. When the two cases of indeterminate cell tumor are added to those previously described in the literature, it appears that 4 of 13 cases (31%) are associated with a history of low grade B-cell malignancy. Possible explanations for the relationship between these two disorders are discussed.

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 Hodgkin's as well as in non-Hodgkin's 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-Hodgkin's lymphomas of B- and T-lineage, classical Hodgkin's lymphomas, and nodular lymphocyte predominant Hodgkin's lymphomas. Our study revealed that all transcription factors were universally expressed in all cases of nodular lymphocyte predominant Hodgkin's and variably expressed in non-Hodgkin's lymphomas of B-lineage. Cases of classical Hodgkin's lymphoma variably expressed the Pax-5, Oct-1, Oct-2, and BOB.1. However, in contrast to nodular lymphocyte predominant Hodgkin's lymphoma, the transcription factor PU.1 was consistently absent in all cases of classical Hodgkin's 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 Hodgkin's lymphomas from nodular lymphocyte predominant Hodgkin's lymphomas in problematic cases.

Enhanced cytomegalovirus infection in atherosclerotic human blood vessels

Human cytomegalovirus (CMV) is a possible co-factor in atherogenesis and vascular occlusion, but its ability to actively infect medium and large blood vessels is unclear. A vascular explant model was adapted to investigate CMV infection in human coronary artery, internal mammary artery (IMA), and saphenous vein (SV). Vascular explants were inoculated with CMV Towne or low-passage clinical isolate and examined in situ for CMV cytopathic effect and immediate-early and early antigens, as indicators of active infection. At 5 to 7 days after inoculation, we found that CMV Towne actively infected eight of eight different atherosclerotic blood vessel explants (coronary artery, n = 4; SV and IMA grafts, n = 4), whereas it only infected 2 of 14 nonatherosclerotic blood vessel explants (SV, n = 10; IMA, n = 4) (P = 0.001). The CMV clinical isolate actively infected none of six sets of nonatherosclerotic SV explants at 5 to 7 days after inoculation. The active CMV infections involved adventitial and, less frequently, intimal cells. A small subset of infected cells in atherosclerotic tissue expresses the endothelial cell marker CD31. Smooth muscle cells residing in both atherosclerotic and nonatherosclerotic blood vessels were free of active CMV infections even after all vascular tissue layers were exposed to the virus. In contrast, active CMV Towne infection was evident at 2 days after inoculation in smooth muscle cells and endothelial cells previously isolated from the SV tissues. We conclude that active CMV infection is enhanced in atherosclerotic blood vessels compared to atherosclerosis-free vascular equivalents, and this viral activity is restricted to subpopulations of intimal and adventitial cells.

Ovarian cancer p53 mutation is associated with tumor microvessel density

OBJECTIVE

The objective of this study was to investigate the relationship between microvessel density, as measured by CD31 staining, and histopathologic factors as well as p53 tumor suppressor gene mutation in ovarian cancer.

METHODS

Ovarian cancers (n = 77) were analyzed for p53 gene mutations and CD31 immunohistochemical expression. Histopathologic and mutational data were related to CD31 staining utilizing the Mantel correlation statistic. The microvessel density was scored by averaging counts from three high-power (200x) fields. Survival was based upon maximizing the hazard ratio.

RESULTS

The mean microvessel density counts based on CD31 staining (vessels/HPF) for each FIGO stage and mutation type are as follows: Stage I (10.2), Stage II (10.7), Stage III (13.8), Stage IV (22.0), wild-type p53 (9.3), missense p53 mutation (14.4), and null p53 mutation (23.1). There was a significant correlation between microvessel density count and FIGO stage (P = 0.026), grade (P = 0.04), and p53 mutation type (P = 0.02). Median survival was more than doubled (6.4 vs 2.9 years; P = 0.009) for tumors with microvessel density counts less than or equal to 14 vessels/HPF.

CONCLUSIONS

These data are consistent with the hypothesis that ovarian cancer p53 mutation functions to directly influence angiogenesis, which in turn compromises disease-specific survival. It also suggests validity to targeting p53 alterations with gene replacement as well as the use of antiangiogenesis agents as novel molecular-based therapeutics for ovarian cancer.

Regulating the Tumor Suppressor Gene Maspin in Breast Cancer Cells

PURPOSE

Mammary epithelial cells and the majority of breast cancer tumors require estrogen for continued growth. Antiestrogen therapy alone, or in combination with other drugs, has long been a common procedure for breast cancer treatment and prophylaxis. Thus, there is a critical need to elucidate the mechanism(s) of action of antiestrogen treatment, especially for patients who are at risk of breast cancer development or who are currently receiving hormone therapy. In this study, we examined the ability of hormones to regulate the expression of a tumor suppressor gene, maspin, which is a serine protease inhibitor (serpin) that plays an important role in mammary gland development and is silenced during breast cancer progression. Specifically, our hypothesis tested the clinical efficacy of tamoxifen to regulate maspin expression.

EXPERIMENTAL DESIGN

We used maspin promoter luciferase reporter plasmids that were transfected into normal human mammary epithelial (HMEC1331) and MCF-7 breast cancer cells, followed by determination of the effect of hormones and their antagonists on maspin promoter activity. At the protein level, cytosolic fractions from both cell types before and after hormone treatment were subjected to Western blot analysis to determine maspin level.

RESULTS AND CONCLUSIONS

Our studies revealed that the antiestrogen tamoxifen induces maspin promoter activity. Interestingly, antiandrogen flutamide could also induce maspin in both cell lines tested. These observations were further confirmed in patient tissues. These novel findings provide a new mechanism of action for tamoxifen under normal and pathological conditions. More significantly, these findings could have a potential impact on future therapeutic intervention strategies for breast cancer.

Surface immunoglobulin light chain-positive acute lymphoblastic leukemia of FAB L1 or L2 type: a report of 6 cases in adults

Acute lymphoblastic leukemia (ALL) of B-cell lineage may be classified using the French-American-British (FAB) classification as L1, L2, or L3 type. L1 and L2 ALLs characteristically express terminal deoxynucleotidyl transferase (TdT) and are surface immunoglobulin (sIg)-negative. In contrast, L3 ALL is typically TdT-negative and sIg-positive. However, in a few large studies of children with ALL, sIg expression has been reported in less than 2% of L1 and L2 neoplasms. In these sIg-positive cases, IgM usually has been detected, with Ig light chain in a subset of tumors. Surface Ig expression in L1 or L2 ALL in adults is extremely rare; we found only 1 case report in the English literature. We report 6 cases of L1 or L2 ALL with an unusual immunophenotype arising in adults. In each tumor, the neoplastic cells expressed monotypic sIg light chain (4 lambda, 2 kappa) and TdT. Three tumors expressed CD34. Cytogenetic studies in 4 cases at diagnosis or relapse revealed no evidence of chromosomal translocations involving the c-myc locus, such as the t(8;14), t(2;8), or t(8;22). Three patients responded completely to chemotherapy and are alive; follow-up ranges from 18 to 57 months. Three patients died at 3, 13, and 14 months after diagnosis.

HER-2 Gene Amplification in Paget Disease of the Nipple and Extramammary Site: A Chromogenic In Situ Hybridization Study

Patients with human epidermal growth factor receptor 2 (HER-2) overexpressing breast carcinomas have a more aggressive clinical behavior and their tumors are often hormone receptor negative. However, the recently introduced anti-HER-2 antibody trastuzumab has been proven to improve the survival and controls the disease in a significant proportion of these patients. Therefore, the analysis of HER-2 in patients with breast cancer has become an important and routine test to select those who may benefit from the gene-based targeted therapy trastuzumab (herceptin). There is good correlation between HER-2/neu protein overexpression and HER-2 gene amplification in breast cancer. However, inconsistent results have been reported in the rate of HER-2/neu protein overexpression in other malignant neoplasms. Furthermore, only rare studies have investigated the correlation between the HER-2/neu protein overexpression and the status of HER-2 gene in these tumors. We investigated the HER-2 gene and protein status in several cases of Paget disease of the nipple and vulva by using a chromogenic in situ hybridization assay and immunohistochemistry. We find that the majority of the Paget disease of the breast demonstrate HER-2 gene amplification, whereas most of the extramammary Paget disease lack HER-2 gene amplification. In addition, our results show a good correlation between HER-2/neu protein overexpression and HER-2 gene amplification in Paget disease of the nipple, but we were unable to confirm this correlation in HER-2/neu protein overexpressing Paget disease of the vulva.

Epstein-Barr virus-associated inflammatory pseudotumor of the spleen: report of two cases and review of the literature

We report two rare examples of Epstein–Barr virus (EBV)-associated inflammatory pseudotumor of the spleen. One patient presented with night sweats, abdominal pain, and weight loss and was found to have a splenic mass on CT scan suspected of lymphoma. The splenic mass in second patient was found incidentally at the time of work up for kidney stones. The pathologic examination of these splenectomy specimens showed similar histologic features. However, the spindle cells were composed of EBV-infected follicular dendritic cells in one case whereas the second case lacked significant follicular dendritic cell proliferation and showed only focal EBV-infected cells suggesting that these proliferations are heterogenous in nature.

Integration of ruxolitinib into dose-intensified therapy targeted against a novel JAK2 F694L mutation in B-precursor acute lymphoblastic leukemia

A 17-year-old girl with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) with persistent minimal residual disease (MRD) who underwent standard chemotherapy was found to have a BCR-ABL1-like gene expression pattern. Genome sequencing revealed a JAK2 mutation not previously described in BCP-ALL and a potential therapeutic target. Due to concern for an on-therapy relapse, the JAK2 inhibitor ruxolitinib was incorporated into a modified chemotherapy backbone to achieve complete remission prior to stem cell transplant. Treatment was well tolerated and she had undetectable MRD prior to a matched allogeneic stem cell transplant and remained in remission at day +100.

Effect of in vivo lymphocyte-depleting strategies on development of lymphoproliferative disorders in children post allogeneic bone marrow transplantation

T cell depletion (TCD) of marrow is a proven method of graft-versus-host disease (GVHD) prophylaxis in allogeneic bone marrow transplantation (BMT). Nonetheless, TCD is associated with an increased risk of developing post transplant lymphoproliferative disorder (PTLD). Between 1986 and 1998, 241 pediatric patients at the University of Iowa underwent BMT using ex vivo TCD of marrow from mismatched related or matched unrelated donors. Additional GVHD prophylaxis included antithymocyte globulin (ATG) or anti lymphocyte globulin (ALG) post transplant (in vivo TCD). A total of 30 cases of PTLD were identified based upon a combination of clinical, histological, and immunological features. Nearly all cases occurred within 3 months post BMT. A statistically significant increase in PTLD incidence was noted for patients treated with ATG vs ALG (33 vs 9%). While grade I-II acute GVHD was more common in patients receiving ATG vs ALG, no difference in grade III-IV GVHD or overall survival was noted between the two groups. Assessment of immune recovery at various times post BMT revealed significantly fewer T cells in the ATG-treated group, suggesting the deleterious effect of ATG may be due to excessive depletion of donor-derived Epstein-Barr virus-specific cytotoxic T cells. Thus, caution should be exercised in the use of anti-T-cell antibody therapy for additional GVHD prophylaxis in the setting of TCD BMT.

HTLV-I-associated granulomatous T-cell lymphoma in a child

Adult T-cell leukemia/lymphoma (ATLL) is a T-cell malignancy closely associated with human T-cell lymphotropic virus-1 (HTLV-I). Because of its long latency period, ATLL occurs almost exclusively in adults. We report a case of a 13-year-old boy with an 8-year history of skin eruptions. After complete evaluation, a diagnosis of HTLV-I-associated lymphoma/leukemia was made. The T-cell lymphoma exhibited a granulomatous histomorphology. There have been very few reports of ATLL presenting in childhood and none, to our knowledge, demonstrating granulomatous histology. We conclude that ATLL may rarely present as a chronic granulomatous eruption in a child.

Risk factors for non-Hodgkin lymphoma subtypes defined by histology and t(14;18) in a population-based case-control study

The t(14;18) chromosomal translocation is the most common cytogenetic abnormality in non-Hodgkin lymphoma (NHL), occurring in 70-90% of follicular lymphomas (FL) and 30-50% of diffuse large B-cell lymphomas (DLBCL). Previous t(14;18)-NHL studies have not evaluated risk factors for NHL defined by both t(14;18) status and histology. In this population-based case-control study, t(14;18) status was determined in DLBCL cases using fluorescence in situ hybridization on paraffin-embedded tumor sections. Polytomous logistic regression was used to evaluate the association between a wide variety of exposures and t(14;18)-positive (N=109) and -negative DLBCL (N=125) and FL (N=318), adjusting for sex, age, race, and study center. Taller height, more lifetime surgeries, and PCB180 exposure were associated with t(14;18)-positivity. Taller individuals (third tertile vs. first tertile) had elevated risks of t(14;18)-positive DLBCL (odds ratio [OR] = 1.8, 95% confidence interval [CI] 1.1-3.0) and FL (OR=1.4, 95%CI 1.0-1.9) but not t(14;18)-negative DLBCL. Similar patterns were seen for individuals with more lifetime surgeries (13+ vs. 0-12 surgeries; t(14;18)-positive DLBCL OR=1.4, 95%CI 0.7-2.7; FL OR=1.6, 95%CI 1.1-2.5) and individuals exposed to PCB180 greater than 20.8 ng/g (t(14;18)-positive DLBCL OR=1.3, 95%CI 0.6-2.9; FL OR=1.7, 95%CI 1.0-2.8). In contrast, termite treatment and high alpha-chlordane levels were associated with t(14;18)-negative DLBCL only, suggesting that these exposures do not act through t(14;18). Our findings suggest that putative associations between NHL and height, surgeries, and PCB180 may be t(14;18)-mediated and provide support for case-subtyping based on molecular and histologic subtypes. Future efforts should focus on pooling data to confirm and extend previous research on risk factors for t(14;18)-NHL subtypes.

Fluorescence Immunophenotyping and Interphase Cytogenetics (FICTION) Detects BCL6 Abnormalities, Including Gene Amplification, in Most Cases of Nodular Lymphocyte-Predominant Hodgkin Lymphoma

Context.— BCL6 translocations are a frequent finding in B-cell lymphomas of diverse subtypes, including some cases of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). However, reliable analysis of BCL6 rearrangements using fluorescence in situ hybridization is difficult in NLPHL because of the relative paucity of neoplastic cells. Combined immunofluorescence microscopy and fluorescence in situ hybridization, or fluorescence immunophenotyping and interphase cytogenetics as a tool for the investigation of neoplasms (FICTION), permits targeted analysis of neoplastic cells.

Objective.—To better define the spectrum of BCL6 abnormalities in NLPHL using FICTION analysis.

Design.—We performed an optimized FICTION analysis of 24 lymph nodes, including 11 NLPHL, 5 follicular hyperplasia with prominent progressive transformation of germinal centers, and 8 follicular hyperplasia without progressive transformation of germinal centers.

Results.— BCL6 rearrangement was identified in 5 of 11 cases of NLPHL (46%). In addition, BCL6 gene amplification, with large clusters of BCL6 signals in the absence of chromosome 3 aneuploidy, was detected in 3 of 11 cases of NLPHL (27%). One NLPHL showed extra copies of BCL6 present in conjunction with multiple copies of chromosome 3. Altogether, we detected BCL6 abnormalities in 9 of 11 cases of NLPHL (82%). None of the progressive transformation of germinal centers or follicular hyperplasia cases showed BCL6 abnormalities by FICTION.

Conclusions.—To our knowledge, this is the first report of BCL6 gene amplification in NLPHL. Our optimized protocol for FICTION permits detection of cytogenetic abnormalities in most NLPHL cases and may represent a useful ancillary diagnostic technique.

Gastric lymphoepithelioma-like carcinoma and jejunal B-cell MALT lymphoma with large cell transformation. Demonstration of EBV with identical LMP gene deletions in the carcinoma and large cell lymphoma

The authors describe a patient with gastric lymphoepithelioma-like carcinoma (LELC) and jejunal low grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) with histologic transformation to large cell lymphoma. In situ hybridization studies for Epstein-Barr virus (EBV) demonstrated abundant EBV RNA (EBER) within the neoplastic cells of the gastric LELC and the jejunal large cell lymphoma. The low grade MALT lymphoma was EBER negative. Polymerase chain reaction (PCR) studies confirmed the in situ hybridization results, and demonstrated a 30 base pair deletion in the 3' end of the latent membrane protein gene in both the gastric LELC and the jejunal large cell lymphoma. These results suggest that the same viral strain infected both the stomach and jejunal tumors. In addition, the finding of EBV in the large cell lymphoma, but not the low grade component suggests that EBV may have played a role in large cell transformation.

Association between Epstein-Barr virus and classic Hodgkin lymphoma in Jordan: a comparative study with Epstein-Barr virus-associated Hodgkin lymphoma in North America

An association between Epstein-Barr virus and Hodgkin lymphoma has been shown in several parts of the world. The reported incidence of Epstein-Barr virus in Hodgkin lymphoma varies significantly from one country to another and ranges from <30% in Swedish patients to 100% in patients from Kenya. Using in situ hybridization for detection of Epstein-Barr virus-encoded RNA and immunohistochemistry for detection of Epstein-Barr virus latent membrane protein, we analyzed 28 cases of Hodgkin lymphoma from Jordan and 30 cases from the United States. Eight of 28 Jordanian cases and 9 of 30 North American cases were Epstein-Barr virus positive. Our studies show that the incidence of Epstein-Barr virus among Jordanian patients with Hodgkin lymphoma is similar to the rate in patients from the United States. This rate appears to be low to intermediate compared with rates in other parts of the world.

Detection of factor V leiden and prothrombin gene mutations in patients who died with thrombotic events

CONTEXT

Individuals with factor V or prothrombin gene mutations are at increased risk for thrombotic events. Furthermore, the risk of recurrent deep venous thrombosis in heterozygous carriers of both factor V Leiden and prothrombin gene mutations is high enough that some investigators suggest lifelong warfarin prophylaxis for these individuals, even with a single spontaneous thrombotic event.

OBJECTIVES

To assess the incidence of factor V Leiden and prothrombin gene mutations in an autopsy population and to determine if these tests can prove useful in identification of at-risk family members.

DESIGN

We analyzed factor V Leiden and prothrombin gene mutations in 45 patients who died with or of thrombotic events, using archival tissue and multiplex allele-specific polymerase chain reaction amplification. The wild-type factor V gene was amplified in all 45 patients, whereas the wild-type prothrombin gene was amplified in 29 patients.

RESULTS

Two patients (4.4%) who died with thrombotic events at the ages of 35 and 92 years were heterozygous for factor V gene mutation. Two additional patients (6.7%), who died with thrombotic events at the ages of 26 and 39 years, were heterozygous for prothrombin gene mutation. Patients homozygous for either factor V or prothrombin gene or simultaneously heterozygous for both genes were not detected in our study.

CONCLUSIONS

Our findings suggest that screening the relatives of elderly patients who die with thrombotic events would not be cost-effective because of the low incidence of these mutations in the autopsy population. However, because the incidence of these mutations appeared significantly more frequently among individuals who died at 39 years or younger, testing the relatives of this subset of patients may prove useful for detection of at-risk individuals who would benefit from preventive anticoagulation therapy.

Comparison of Tissue Molecular Biomarker Testing Turnaround Times and Concordance Between Standard of Care and the Biocartis Idylla Platform in Patients With Colorectal Cancer

OBJECTIVES

Management of colorectal cancer warrants mutational analysis of KRAS/NRAS when considering anti-epidermal growth factor receptor therapy and BRAF testing for prognostic stratification. In this multicenter study, we compared a fully integrated, cartridge-based system to standard-of-care assays used by participating laboratories.

METHODS

Twenty laboratories enrolled 874 colorectal cancer cases between November 2017 and December 2018. Testing was performed on the Idylla automated system (Biocartis) using the KRAS and NRAS-BRAF cartridges (research use only) and results compared with in-house standard-of-care testing methods.

RESULTS

There were sufficient data on 780 cases to measure turnaround time compared with standard assays. In-house polymerase chain reaction (PCR) had an average testing turnaround time of 5.6 days, send-out PCR of 22.5 days, in-house Sanger sequencing of 14.7 days, send-out Sanger of 17.8 days, in-house next-generation sequencing (NGS) of 12.5 days, and send-out NGS of 20.0 days. Standard testing had an average turnaround time of 11 days. Idylla average time to results was 4.9 days with a range of 0.4 to 13.5 days.

CONCLUSIONS

The described cartridge-based system offers rapid and reliable testing of clinically actionable mutation in colorectal cancer specimens directly from formalin-fixed, paraffin-embedded tissue sections. Its simplicity and ease of use compared with other molecular techniques make it suitable for routine clinical laboratory testing.

Recommendations for gross examination and sampling of surgical specimens of the spleen

This review examines handling and processing of spleen biopsies and splenectomy specimens with the aim of providing the pathologist with guidance in optimizing examination and diagnosis of splenic disorders. It also offers recommendations as to relevant reporting factors in gross examination, which may guide diagnostic workup. The role of splenic needle biopsies is discussed. The International Spleen Consortium is a group dedicated to promoting education and research on the anatomy, physiology, and pathology of the spleen. In keeping with these goals, we have undertaken to provide guidelines for gross examination, sectioning, and sampling of spleen tissue to optimize diagnosis (Burke). The pathology of the spleen may be complicated in routine practice due to a number of factors. Among these are lack of familiarity with lesions, complex histopathology, mimicry within several types of lesions, and overall rarity. To optimize diagnosis, appropriate handling and processing of splenic tissue are crucial. The importance of complete and accurate clinical history cannot be overstated. In many cases, significant clinical history such as previous lymphoproliferative disorders, hematologic disorders, trauma, etc, can provide important information to guide the evaluation of spleen specimens. Clinical information helps plan for appropriate processing of the spleen specimen. The pathologist should encourage surgical colleagues, who typically provide the specimens, to include as much clinical information as possible.

Pyrosequencing for classification of human FcγRIIIA allotypes: a comparison with PCR-based techniques

BACKGROUND

Surface-specific antigens expressed by hematopoietic cells are attractive targets for antibody-mediated immunotherapy. Monoclonal antibodies (mAbs) involve various mechanisms to eliminate target cells, including antibody-dependent cellular cytotoxicity (ADCC)- and phagocytosis (ADCP)-mediated killing through natural killer (NK) and macrophage effector cells bearing FcγRIIIA (CD16). The clinical efficacy of ADCC is particularly impacted by a single nucleotide polymorphism (SNP) found in the gene encoding FcγRIIIA (FCGR3A), which generates a variable distribution of the 158 V/V, F/V or F/F CD16 allotypes (F = phenylalanine, V = valine) in the normal human population. Currently, most patients are not screened for CD16 allotypes, creating the potential to include in their treatment a mAb-based therapy that may have limited benefit. Therefore, it is important to identify CD16 allotypes when considering mAb therapies that require ADCC/ADCP.

OBJECTIVE

The objective of this study was to develop a reliable PCR-based assay for classification of human FcγRIIIA allotypes.

METHODS

We studied 42 normal human subjects for the incidence of FcγRIIIA-158 polymorphisms using comparative molecular approaches.

RESULTS

The results of our study showed 100% accuracy in genotyping by pyrosequencing. In contrast, nested PCR-based allele-specific restriction assay and quantitative PCR techniques proved to be relatively less sensitive and less specific in distinguishing variant genotypes.

CONCLUSION

Since the efficacy of the mAb-based targeted immunotherapy may be highly dependent upon the CD16 polymorphism in a given individual, we recommend pyrosequencing for CD16 allotype testing.

LIM domain only 2 protein expression, LMO2 germline genetic variation, and overall survival in diffuse large B-cell lymphoma in the pre-rituximab era

Both LMO2 (LIM domain only 2) mRNA and protein expression in diffuse large B-cell lymphoma (DLBCL) have been associated with superior survival. However, a role for germline genetic variation in LMO2 has not been previously reported. Immunohistochemistry (IHC) for LMO2 was conducted on tumor tissue from diagnostic biopsies, and 20 tag single nucleotide polymorphisms (SNPs) from LMO2 were genotyped from germline DNA. LMO2 IHC positivity was associated with superior survival (hazard ratio [HR] = 0.55; 95% confidence interval [CI] 0.31-0.97). Four LMO2 SNPs (rs10836127, rs941940, rs750781, rs1885524) were associated with survival after adjusting for LMO2 IHC and clinical factors (p < 0.05), and one of these SNPs (rs941940) was also associated with IHC positivity (p = 0.02). Compared to a model with clinical factors only (c-statistic = 0.676), adding the four SNPs (c-statistic = 0.751) or LMO2 IHC (c-statistic = 0.691) increased the predictive ability of the model, while inclusion of all three factors (c-statistic = 0.754) did not meaningfully add predictive ability above a model with clinical factors and the four SNPs. In conclusion, germline genetic variation in LMO2 was associated with DLBCL prognosis and provided slightly stronger predictive ability relative to LMO2 IHC status.