Evaluation of clinical parameters and biomarkers in older, untreated mantle cell lymphoma patients receiving bendamustine-rituximab.

Mantle cell lymphoma (MCL) is clinically and biologically heterogeneous. While various prognostic features have been proposed, none currently impact therapy selection, particularly in older patients, for whom treatment is primarily dictated by age and comorbidities. Herein, we undertook a comprehensive comparison of clinicopathological features in a cohort of patients 60 years and older, uniformly treated with bendamustine and rituximab, with a median survival of >8 years. The strongest prognostic indicators in this cohort were a high-risk call by a simplified MCL international prognostic index (s-MIPI) (HR: 3.32, 95% CI: 1.65-6.68 compared to low risk), a high-risk call by MCL35 (HR: 10.34, 95% CI: 2.37-45.20 compared to low risk) and blastoid cytology (HR: 4.21, 95% CR: 1.92-9.22 compared to classic). Patients called high risk by both the s-MIPI and MCL35 had the most dismal prognosis (HR: 11.58, 95% CI: 4.10-32.72), while those with high risk by either had a moderate but clinically relevant prognosis (HR: 2.95, 95% CI: 1.49-5.82). A robust assay to assess proliferation, such as MCL35, along with stringent guidelines for cytological evaluation of MCL, in combination with MIPI, may be a strong path to risk-stratify older MCL patients in future clinical trials.

Transformation of FL into DLBCL with a PMBL gene expression signature.

We investigated the clinicopathologic features of 5 follicular lymphomas (FLs) that transformed (tFL) morphologically to diffuse large B-cell lymphomas (DLBCLs) and had a primary mediastinal large B-cell lymphoma (PMBL)-like gene expression profile (tFL-PMBLsig-pos). None of the tFL-PMBLsig-pos cases arose in the mediastinum, all cases tested had a germinal center B-cell phenotype, 20% were CD30+, 60% CD23+, 80% MAL+, 20% CD200+, and 0% CD273/PDL2+. Whole-exome sequencing detected alterations in genes associated with both FL/DLBCL (CREBBP, KMT2C, KMT2D, ARID1A, HIST1 members, and TNFRSF14) and PMBL (JAK-STAT pathway genes, B2M, and CD58). Copy number (CN) analysis detected gains/amplification of REL and STAT6 in 60%, gains of SOCS1 in 40%, and gains of chromosome 16, including IL4R, in 40% of the cases. CN gains/amplification of BCL6 and MYC and loss of TNFRSF14 and TNFAIP3 were identified in 20% of the cases. Three of 5 cases lacked a BCL2 rearrangement. Despite having some features that are less common in DLBCL (MAL and CD23 expression and JAK-STAT activation), these tFL-PMBLsig-pos cases lack the most characteristic CN alteration seen in PMBL (9p24.1 gain/amplification). This cohort expands the biologic heterogeneity of tFL, illustrating a subset with gene expression and some genetic features reminiscent of PMBL, with potential treatment implications that include the use of novel targeted therapies.

Myeloid Sarcoma of the Temporal Bone: A Unique Cause of Hearing Loss, Otalgia, and Facial Nerve Weakness.

OBJECTIVE: To characterize a clinical triad of symptoms associated with myeloid sarcomas of the temporal bone via a review of all previously reported cases. METHODS: Case report and Ovid MEDLINE database literature review. RESULTS: A literature search revealed that a clinical triad of hearing loss, otalgia, and facial nerve weakness are commonly associated with this rare presentation of myeloid sarcoma in the temporal bone. 44% (18/41) of patients presented with all three symptoms, while 76% (31/41) presented with at least two. The presence of t(8;21) was reported in nine patients with myeloid sarcomas of the temporal bone. CONCLUSIONS: Although myeloid sarcomas are exceedingly rare, it is necessary to consider them as part of the differential diagnosis for patients who might present with middle ear and mastoid opacification on computed tomography (CT) scan, hearing loss, otalgia, and facial nerve palsy. Physicians should maintain a high degree of suspicion in patients with a history of acute myelogenous leukemia (AML), especially if previous cytogenetic analysis revealed a t(8;21).

Donor cell-derived chronic myelomonocytic leukemia presenting after allogeneic hematopoietic cell transplantation for T-cell acute lymphoblastic leukemia.

Donor cell leukemia is a very rare cause of relapse after allogeneic hematopoietic cell transplantation (alloHCT). Herein, we describe an unprecedented case of donor cell-derived chronic myelomonocytic leukemia (CMML) presenting seven years after a 51-year-old man received a matched-related alloHCT from his 59-year-old brother for T-cell acute lymphoblastic leukemia.

Clinical laboratory validation of the MCL35 assay for molecular risk stratification of mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a clinically heterogeneous B cell malignancy for which a variety of prognostic factors have been proposed. Previously, a digital gene expression profiling "proliferation signature" capable of risk stratifying MCL was identified and subsequently developed into a multi-analyte prognostic assay, known as the "MCL35" assay. In this study, we sought to explore the performance characteristics of the MCL35 assay in a clinical laboratory and compare results with the Ki67 proliferation marker. The results describe the clinical validation of the MCL35 assay for molecular risk stratification of MCL including accuracy, sensitivity, specificity, use in acid-decalcified bone marrow core biopsies, fixatives, lower limit of RNA input, quality metrics, and other laboratory parameters. The resulting data indicate that this is a robust technique with outstanding reproducibility. Overall, the data support the concept of molecular signatures, as assessed with digital gene expression profiling, for improved standardization and reproducibility for proliferation assessment in MCL.

Incorporation of Digital Gene Expression Profiling for Cell-of-Origin Determination (Lymph2Cx Testing) into the Routine Work-Up of Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphomas (DLBCL) represent a clinically heterogeneous group of lymphomas that are classified together based on similarities in morphology and immunophenotype. Gene expression profiling further classifies DLBCL into distinct molecular subgroups based on cell-of-origin (COO), including Germinal Center B-cell type, Activated B-cell type, and Unclassified type. COO assignment of DLBCL has important biological and prognostic significance, as well as emerging therapeutic implications. Herein, we describe the first clinical validation of a digital gene expression profiling assay (Lymph2Cx) to perform COO assignment in the routine work-up of DLBCL using formalin-fixed paraffin-embedded (FFPE) tissue sections and describe the results of 90 consecutive DLBCL cases analyzed prospectively by a College of American Pathologists/Clinical Laboratory Improvement Amendments (CAP/CLIA)-certified clinical molecular diagnostics laboratory.

Profiling of lymphoma from formalin-fixed paraffin-embedded tissue.

Molecular profiling of lymphoma samples has contributed enormously to our understanding of disease biology leading to detailed descriptions of diagnostic categories. These studies have also helped the field to recognize different subtypes of disease, different diseases that share similar cellular pathway perturbations, different immune responses, and different prognostic groups. While nearly all of these discoveries were made using unfixed, snap-frozen materials, with few exceptions, clinical biopsy materials are comprised of formalin-fixed and paraffin-embedded (FFPE) tissues. Here, we describe the impact of molecular profiling on the field of lymphoma, the challenges associated with using FFPE tissues for downstream molecular diagnostic testing, the various molecular profiling techniques, and also provide an example of the clinical application of a molecular profiling test of lymphoma using FFPE tissues.

Immunophenotypic and cytogenetic findings of B-lymphoblastic leukemia/lymphoma associated with combined IGH/BCL2 and MYC rearrangement.

BACKGROUND: B-lymphoblastic leukemias (B-LBL) with combined IGH/BCL2 and MYC rearrangement are rare and their clinical, cytogenetic and immunophenotypic features are not well characterized. Here, we describe a case of a 61-year-old woman with B-LBL associated with these cytogenetic alterations and present a review of the literature of this disease. METHODS: Four-color flow cytometry (FC) was performed on a BD FACSCanto II flow cytometer. Data were analyzed with BD FACSDiva software. Cytogenetic, fluorescence in situ hybridization (FISH), and molecular studies were performed by conventional methods. A review of the literature was performed by a PubMed-assisted search. RESULTS: Including our case, eight B-LBLs associated with a documented "double-hit" karyotype (IGH/BCL2 and 8q24/MYC rearrangement) were identified in the literature (male/female 2/6, age 15-65). Three occurred de-novo, and five had a history of a CD10+ B-cell lymphoma. The typical immunophenotype was CD10, CD19, TdT positive, and negative for CD34 and surface immunoglobulin (Ig), established either by FC or immunohistochemistry. Seven cases were CD20-, and one case was CD20+. Translocation partners of MYC varied, and included IGH, lambda light chain, and an unknown gene on chromosome 9. Prognosis was poor with median survival of five months. CONCLUSIONS: Patients with B-LBL associated with a combined IGH/BCL2 and MYC rearrangement often have a history of a mature B-cell lymphoma. The immunophenotype of these cases is different from that of mature "double-hit" lymphomas; FC is essential to differentiate the B-LBL cases from the leukemic phase of mature B-cell lymphomas. © 2015 International Clinical Cytometry Society.

College of American Pathologists' laboratory standards for next-generation sequencing clinical tests.

CONTEXT: The higher throughput and lower per-base cost of next-generation sequencing (NGS) as compared to Sanger sequencing has led to its rapid adoption in clinical testing. The number of laboratories offering NGS-based tests has also grown considerably in the past few years, despite the fact that specific Clinical Laboratory Improvement Amendments of 1988/College of American Pathologists (CAP) laboratory standards had not yet been developed to regulate this technology. OBJECTIVE: To develop a checklist for clinical testing using NGS technology that sets standards for the analytic wet bench process and for bioinformatics or "dry bench" analyses. As NGS-based clinical tests are new to diagnostic testing and are of much greater complexity than traditional Sanger sequencing-based tests, there is an urgent need to develop new regulatory standards for laboratories offering these tests. DESIGN: To develop the necessary regulatory framework for NGS and to facilitate appropriate adoption of this technology for clinical testing, CAP formed a committee in 2011, the NGS Work Group, to deliberate upon the contents to be included in the checklist. Results . -A total of 18 laboratory accreditation checklist requirements for the analytic wet bench process and bioinformatics analysis processes have been included within CAP's molecular pathology checklist (MOL). CONCLUSIONS: This report describes the important issues considered by the CAP committee during the development of the new checklist requirements, which address documentation, validation, quality assurance, confirmatory testing, exception logs, monitoring of upgrades, variant interpretation and reporting, incidental findings, data storage, version traceability, and data transfer confidentiality.

Detection of clonal immunoglobulin heavy chain gene rearrangements by the polymerase chain reaction and capillary gel electrophoresis.

Although well-established diagnostic criteria exist for mature B-cell neoplasms, a definitive diagnosis of a B-cell lymphoproliferative disorder cannot always be obtained using more conventional techniques such as flow cytometric immunophenotyping, conventional cytogenetics, fluorescence in situ hybridization, or immunohistochemistry. However, because B-cell malignancies contain identically rearranged immunoglobulin heavy chain genes, the polymerase chain reaction (PCR) can be a fast, convenient, and dependable option to identify clonal B-cell processes. This chapter describes the use of PCR and capillary electrophoresis to identify clonal immunoglobulin heavy chain (IGH) variable and joining region (VH-JH) gene rearrangements (IGH VH-JH PCR) using a commercially available method employing multiple multiplex PCR tubes that was originally developed as the result of a large European BIOMED-2 collaborative study (Invivoscribe Technologies). The core protocol involves the use of three separate master mix tubes that target the conserved framework (FR1, FR2, and FR3) and joining (J) regions of the IGH gene. Analysis of these three framework regions can detect approximately 88% of clonal IGH gene rearrangements.

Detection of clonal T-cell receptor beta and gamma chain gene rearrangement by polymerase chain reaction and capillary gel electrophoresis.

Although established diagnostic criteria exist for mature T-cell neoplasms, a definitive diagnosis of a T-cell lymphoproliferative disorder cannot always be obtained using more conventional techniques such as flow cytometric immunophenotyping, conventional cytogenetics, fluorescence in situ hybridization, or immunohistochemistry. However, because T-cell malignancies contain identically rearranged T-cell receptor gamma (TCRG) and/or beta (TCRB) genes, the polymerase chain reaction (PCR) can be a fast, convenient, and dependable option to identify clonal T-cell processes. This chapter describes the use of PCR and capillary electrophoresis to identify clonal TCRB and TCRG gene rearrangements (TCRB and TCRG PCR) using a commercially available method employing multiple multiplex PCR tubes that was originally developed as the result of a large European BIOMED-2 collaborative study (Invivoscribe Technologies). The core protocol for the TCRB assay involves the use of three separate multiplex master mix tubes. Tubes A and B target the framework regions within the variable and joining regions of the TCRB gene, and Tube C targets the diversity and joining regions of the TCRB gene. The core protocol for the TCRG assay utilizes two multiplex master mix tubes (Tubes A and B) that target the variable and joining regions of the TCRG gene. Use of the five BIOMED-2 TCRB and TCRG PCR multiplex tubes in parallel can detect approximately 94% of clonal TCR gene rearrangements.

Epstein-Barr virus (EBV) load determination using real-time quantitative polymerase chain reaction.

Epstein-Barr virus (EBV) infects virtually the entire human population and infection persists throughout the lifetime of its host. EBV has been associated with the development of a wide variety of neoplasms, including lymphoma, carcinoma, and sarcoma. In addition, EBV-associated lymphoproliferative disorders are particularly prevalent in immunosuppressed individuals, including AIDS patients, transplant recipients, and patients with congenital immunodeficiencies. In recent years, EBV viral load assessment has been extensively implemented in clinical practice for the diagnosis and monitoring of EBV-associated malignancies and lymphoproliferative disorders. The real-time quantitative polymerase chain reaction (RQ-PCR) has become the method of choice for quantification of specific EBV nucleic acid sequences. This method is fast, extremely sensitive, and accurate, requires only very small amounts of input nucleic acid, and is relatively simple to perform. These characteristics have made it the method of choice for EBV viral load determination. This chapter describes the use of a laboratory-developed RQ-PCR EBV viral load assay for the detection of EBV DNA in cell-free plasma and cerebrospinal fluid samples.

Acute systemic viral infection masquerading as an infiltrating lymphoma in an elderly patient: a case report and review of the literature.

Primary Epstein-Barr virus (EBV) infection occurs mainly in adolescents and young adults, with more than 90% of adults having serological evidence of past infection. Primary infection in those over the age of 40 is associated with an atypical and often more severe presentation that can lead to more extensive and invasive, and often unnecessary, diagnostic testing. The incidence of severe EBV-related illness in older adults has been observed to be increasing in industrialized nations. The characteristic presentation of infectious mononucleosis (IM) syndrome in elderly patients (age > 65) is not clearly defined in the literature. Here, we describe a case of primary EBV infection in an 80-year-old female and review the literature regarding primary seroconversion in elderly patients.

Real-time quantitative reverse transcriptase polymerase chain reaction.

The real-time quantitative reverse transcriptase polymerase chain reaction (RQ-PCR) has become the method of choice for the quantification of specific mRNAs. This method is fast, extremely sensitive, and accurate, requires only very small amounts of input RNA, and is relatively simple to perform. These characteristics have made it the method of choice for minimal residual disease monitoring such as in chronic myelogenous leukemia (CML). CML comprises approximately 20% of all leukemias and is characterized by a balanced (9;22) chromosomal translocation that results in the formation of a chimeric gene comprised of the BCR (breakpoint cluster region) gene and the ABL oncogene (BCR-ABL fusion gene). The chimeric gene encodes a fusion protein with constitutively increased tyrosine kinase activity, resulting in growth factor-independent proliferation. This kinase is the target for current CML therapy, and BCR-ABL fusion gene levels are monitored to determine the effectiveness of this therapy. This chapter uses BCR-ABL transcript detection to illustrate an example for the RQ-PCR and describes a RQ-PCR method to detect the most common form of the BCR-ABL fusion transcript in CML, known as p210 BCR-ABL.

Clinical validation of an array CGH test for HER2 status in breast cancer reveals that polysomy 17 is a rare event.

The HER2 gene is an important prognostic and therapeutic marker in newly diagnosed breast cancer. Currently, HER2 status is most frequently determined by immunohistochemical detection of HER2 protein expression on the cellular membrane surface or by fluorescence in situ hybridization analysis of HER2 gene copy number in fixed tissue using locus-specific probes for the HER2 gene and chromosome 17 centromere. However, these methods are problematic because of issues with intra- and inter-laboratory reproducibility and preanalytic variables, such as fixation time. In addition, the commonly used HER2/chromosome 17 ratio presumes that chromosome 17 polysomy is present when the centromere is amplified, even though analysis of the rest of the chromosome is not included in the assay. In this study, 97 frozen samples of invasive lobular and invasive ductal carcinoma, with known immunohistochemistry and fluorescence in situ hybridization results for HER2, were analyzed by comparative genomic hybridization to a commercially available bacterial artificial chromosome whole-genome array containing 99 probes targeted to chromosome 17 and the HER2/TOP2 amplicon. Results were 97% concordant for HER2 status, meeting the College of American Pathologists/American Society of Clinical Oncology's validation requirements for HER2 testing. Surprisingly, not a single case of complete polysomy 17 was detected even though multiple breast cancer cases showed clear polysomies of other chromosomes. We conclude that array comparative genomic hybridization is an accurate and objective DNA-based alternative for clinical evaluation of HER2 gene copy number, and that polysomy 17 is a rare event in breast cancer.

Copy number abnormalities, MYC activity, and the genetic fingerprint of normal B cells mechanistically define the microRNA profile of diffuse large B-cell lymphoma.

MicroRNA (miRNA) deregulation contributes to cancer pathogenesis. However, analysis of miRNAs in diffuse large B-cell lymphoma (DLBCL) has been hindered by a focus on cell lines, limited number of miRNAs examined, and lack of copy number data. To address these restrictions, we investigated genomewide miRNA expression and copy number data in 86 DLBCLs. Permutation analysis showed that 63 miRNAs were recurrently disrupted in DLBCL, including highly expressed oncomirs not previously linked to chromosomal abnormalities. Further, using training and validation tumor groups, we defined a collection of miRNAs that robustly segregates DLBCLs into 3 subsets, which are independent of the cell-of-origin classification, extent of T-cell infiltrate, and tumor site. Instead, these unique miRNA-driven DLBCL subgroups showed markedly different MYC transcriptional activity, which explained the dominance of miRNAs regulated by MYC in their expression signatures. In addition, analysis of miRNA expression patterns of normal B cells and integration of copy number and expression data showed that genomic abnormalities and the genetic fingerprint of nonmalignant cells also contribute to the miRNA profile of DLBCL. In conclusion, we created a comprehensive map of the miRNA genome in DLBCL and, in the process, have uncovered and mechanistically elucidated the basis for additional molecular heterogeneity in this tumor.

Array CGH analysis of chronic lymphocytic leukemia reveals frequent cryptic monoallelic and biallelic deletions of chromosome 22q11 that include the PRAME gene.

We used BAC array-based CGH to detect genomic imbalances in 187 CLL cases. Submicroscopic deletions of chromosome 22q11 were observed in 28 cases (15%), and the frequency of these deletions was second only to loss of the 13q14 region, the most common genomic aberration in CLL. Oligonucleotide-based array CGH analysis showed that the 22q11 deletions ranged in size from 0.34 Mb up to approximately 1 Mb. The minimally deleted region included the ZNF280A, ZNF280B, GGTLC2, and PRAME genes. Quantitative real-time PCR revealed that ZNF280A, ZNF280B, and PRAME mRNA expression was significantly lower in the 22q11 deletion cases compared to non-deleted cases.

Clinical application of array-based comparative genomic hybridization for the identification of prognostically important genetic alterations in chronic lymphocytic leukemia.

Genomic aberrations have increasingly gained attention as prognostic markers in B-cell chronic lymphocytic leukemia (CLL). Fluorescence in situ hybridization (FISH) has improved the detection rate of genomic alterations in CLL from approximately 50% using conventional cytogenetics to greater than 80%. More recently, array comparative genomic hybridization (CGH) has gained popularity as a clinical tool that can be applied to detect genomic gains and losses of prognostic importance in CLL. Array CGH and FISH are particularly useful in CLL because genomic gains and losses are key events with both biologic and prognostic significance, while balanced translocations have limited prognostic value. Although FISH has a higher technical sensitivity, it requires separate, targeted hybridizations for the detection of alterations at genomic loci of interest. Array CGH, on the other hand, has the ability to provide a genome-wide survey of genomic aberrations with a single hybridization reaction. Array CGH is expanding the known genomic regions of importance in CLL and allows these regions to be evaluated in the context of a genome-wide perspective. Ongoing clinical trials are evaluating the use of genomic aberrations as tools for risk-stratifying patients for therapy, thus increasing the need for reliable and high-yield methods to detect these genomic changes. In this review, we consider the use of array CGH as a clinical tool for the identification of genomic alterations with prognostic significance in CLL, and suggest ways to integrate this test into the clinical molecular diagnostic laboratory work flow.

Whole-genome scanning by array comparative genomic hybridization as a clinical tool for risk assessment in chronic lymphocytic leukemia.

Array-based comparative genomic hybridization (array CGH) provides a powerful method for simultaneous genome-wide scanning and prognostic marker assessment in chronic lymphocytic leukemia (CLL). In the current study, commercially available bacterial artificial chromosome and oligonucleotide array CGH platforms were used to identify chromosomal alterations of prognostic significance in 174 CLL cases. Tumor genomes were initially analyzed by bacterial artificial chromosome array CGH followed by confirmation and breakpoint mapping using oligonucleotide arrays. Genomic changes involving loci currently interrogated by fluorescence in situ hybridization (FISH) panels were detected in 155 cases (89%) at expected frequencies: 13q14 loss (47%), trisomy 12 (13%), 11q loss (11%), 6q loss (7.5%), and 17p loss (4.6%). Genomic instability was the second most commonly identified alteration of prognostic significance with three or more alterations involving loci not interrogated by FISH panels identified in 37 CLL cases (21%). A subset of 48 CLL cases analyzed by six-probe FISH panels (288 total hybridizations) was concordant with array CGH results for 275 hybridizations (95.5%); 13 hybridizations (4.5%) were discordant because of clonal populations that comprised less than 30% of the sample. Array CGH is a powerful, cost-effective tool for genome-wide risk assessment in the clinical evaluation of CLL.