Epidemiological and clinical features of adult T‐cell leukemia–lymphoma in Japan, 2010–2011: A nationwide survey

Adult T‐cell leukemia–lymphoma (ATL) is a mature T‐cell malignancy associated with human T‐cell leukemia virus type 1 (HTLV‐1) infection. Japan is the most endemic country for HTLV‐1 and ATL in the world. Recent nationwide studies of Japanese blood donors reported that HTLV‐1 carriers spread from endemic areas to non‐endemic areas. Therefore, the latest information on nationwide epidemiological and clinical data for ATL is necessary to guide clinical practice. We undertook a multicenter, hospital‐based survey of newly diagnosed ATL patients from 2010 to 2011. A total of 996 patients with ATL were registered from 126 hospitals across Japan. Of those, 922 (487 men and 435 women) were included in the analysis. The median age at diagnosis was 68 years (interquartile range, 60–75 years). Overall, 67.2% of ATL was diagnosed in the Kyushu–Okinawa area. The most common subtype was acute (49.5%), followed by lymphoma (25.7%), chronic (14.2%), and smoldering (10.6%). Lymphoma type was more prevalent in men (60%), whereas chronic was more prevalent in women (60%). Half of patients with lymphoma type were aged over 70 years, whereas one‐third of patients with the chronic type were aged under 60 years. All of these characteristics were different from those of the previous nationwide surveys in the 1980s and 1990s. This survey clarified that half of current patients with ATL are aged over 68 years who were unable to receive intensive cytotoxic therapies. New less toxic agents for aged patients and further strategies to prevent the development of ATL from HTLV‐1 carrier status are needed.     

Mogamulizumab for relapsed adult T‐cell leukemia–lymphoma: Updated follow‐up analysis of phase I and II studies

The present study sought to elucidate the prognosis of adult T‐cell leukemia–lymphoma (ATL) patients receiving mogamulizumab, a defucosylated anti‐CCR4 monoclonal antibody. Progression‐free survival (PFS) and overall survival (OS) of ATL patients enrolled in two studies are herein updated, namely NCT00355472 (phase I study of mogamulizumab in relapsed patients with ATL and peripheral T‐cell lymphoma) and NCT00920790 (phase II study for relapsed ATL). Of 13 patients with relapsed aggressive ATL in the phase I study, four (31%) survived >3 years. For 26 relapsed patients with aggressive ATL in the phase II study, median PFS was 5.2 months and 1‐year PFS was 26%, whereas median OS was 14.4 months, and 3‐year OS was 23%. For patients without a rash or who developed a grade 1 rash only, median PFS was 0.8 months, and 1‐year PFS was zero, with a median OS of 6.0 months, and 3‐year OS of 8%. In contrast, for patients who developed a rash ≥grade 2, median PFS was 11.7 months, and 1‐year PFS was 50%, with a median OS of 25.6 months, and 3‐year OS of 36%. Thus, we conclude that mogamulizumab monotherapy may improve PFS and OS in some patients with relapsed aggressive ATL, especially those who develop a skin rash as a moderate immune‐related adverse event. Therefore, further investigation is warranted to validate the present observations and to clarify the mechanisms involved in the activity of mogamulizumab.     

Recent advances in the treatment of adult T‐cell leukemia‐lymphomas

Recent advances in treatment for adult T‐cell leukemia‐lymphoma (ATL) are reviewed herein. It is currently possible to select a therapeutic strategy for ATL and predict prognosis by classification of patients by clinical subtypes and clinicopathological factors. Although the overall survival (OS) of patients with ATL has increased marginally because of advances in chemotherapy, further prolongation of survival might be difficult with conventional chemotherapy alone. Promising results have been reported for antiviral therapy using zidovudine and interferon‐α, and, indeed, antiviral therapy is currently the standard treatment for patients with ATL in western countries. Remarkably, the 5‐year OS rates are 100% for both the smoldering‐type and chronic‐type ATL. Recently, treatments for ATL have included allogeneic hematopoietic stem cell transplantation and molecular targeted therapies. Furthermore, the anti‐CCR4 monoclonal antibody mogamulizumab has been shown to have marked cytotoxic effects on ATL cells, especially in the leukemic type of ATL. In the lymphoma type of ATL, the response rate may be improved by combining mogamulizumab with chemotherapy. It should be recognized that prevention of infection from carriers of human T‐cell leukemia virus type‐I and transfer of the virus from mother to infant are crucial issues for the eradication of ATL.     

Crucial role of carbonic anhydrase IX in tumorigenicity of xenotransplanted adult T‐cell leukemia‐derived cells

Carbonic anhydrase IX (CA9) is a membrane‐associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T‐cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1‐N6 subline from the ATL‐derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1‐N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1‐CA9^high and ST1‐CA9^low sublines. ST1‐CA9^high cells, like ST1‐N6 cells, were more strongly tumorigenic than ST1‐CA9^low or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1‐CA9^high cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild‐type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9⁺CD25⁺ cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL‐derived cells and may be involved in malignant development of lymphoma‐type ATL.     

Burkitt lymphoma versus diffuse large B‐cell lymphoma: a practical approach

Burkitt Lymphoma (BL) is listed in the World Health Organization (WHO) classification of lymphoid tumours as an ‘aggressive B‐cell non‐Hodgkin's lymphoma’, characterized by a high degree of proliferation of the malignant cells and deregulation of the c‐MYC gene. The main diagnostic challenge in BL is to distinguish it from diffuse large B‐cell lymphoma (DLBCL). While in children BL and DLBCL types probably do not differ clinically, and the differential diagnosis between BL and DLBCL may theoretically appear clear‐cut, in adults daily practice shows the existence of cases that have morphological features, immunophenotypic and cytogenetics intermediate between DLBCL and BL, and cannot be classified with certainty in these categories. Distinguishing between BL and DLBCL is critical, as the two diseases require different management. This review summarizes the current practical approach, including the use of a large panel of antibodies, and cytogenetic and molecular diagnostic techniques, to distinguish between BL, DLBCL and the provisional category of ‘B‐cell lymphoma, unclassifiable, with features intermediate between diffuse large B‐cell lymphoma and Burkitt lymphoma’, now listed in the updated WHO classification. Copyright © 2009 John Wiley & Sons, Ltd.     

Advanced human T‐cell leukemia virus type 1 carriers and early‐stage indolent adult T‐cell leukemia‐lymphoma are indistinguishable based on CADM1 positivity in flow cytometry

We previously reported that the cell adhesion molecule 1 (CADM1) versus CD7 plot in flow cytometry reflects disease progression in human T‐cell leukemia virus type 1 (HTLV‐1) infection. In CD4⁺ cells from peripheral blood, CADM1^?CD7⁺ (P), CADM1⁺CD7^dim (D) and CADM1⁺CD7^? (N) subpopulations are observed. The D and N subpopulations increase as asymptomatic HTLV‐1 carriers (AC) progress to indolent adult T‐cell leukemia‐lymphoma (ATL) and the N subpopulation then expands in aggressive ATL. In the present study we examined whether the analysis can estimate the risk of developing ATL in advanced AC. Peripheral blood samples from AC (N = 41) and indolent ATL patients (N = 19) were analyzed by flow cytometry using the CADM1 versus CD7 plot for CD4⁺ cells and inverse long PCR (clonality analysis) of FACS‐sorted subpopulations. Almost all AC with a high HTLV‐1 proviral load (>4 copies/100 cells) had a CADM1⁺ (D + N) frequency of >10%. AC with 25% < CADM1⁺ ≤ 50% contained expanded clones similar to smoldering‐type ATL. In many patients in the 25% < CADM1⁺ ≤ 50% group, the proportion of abnormal lymphocytes was distributed around the 5% line, which divides AC and smoldering‐type ATL in Shimoyama's classification. In conclusion, the CADM1 versus CD7 plot is useful for selection of putative high‐risk AC. The characteristics of some AC and smoldering ATL are said to be similar; however, long‐term follow up is required and the clinical outcome (e.g. rate of transformation) of these cases should be used to determine whether to include them in the same clinical category.     

Acetylcholinesterase in cultured human leukemia/lymphoma cell lines

Fifty-two cultured leukemia/lymphoma cell lines were studied for their acetylcholinesterase activity. There was a striking effect of maturity on enzyme activity, only the most mature cells showing significant activity. Mature T cells exhibited far more enzyme activity than mature B cells, paralleling results on normal T and B cells.     

Burkitt lymphoma versus diffuse large B‐cell lymphoma: a practical approach

Burkitt Lymphoma (BL) is listed in the World Health Organization (WHO) classification of lymphoid tumours as an “aggressive B‐cell non‐Hodgkin's lymphoma”, characterized by a high degree of proliferation of the malignant cells and deregulation of the c‐MYC gene. The main diagnostic challenge in BL is to distinguish it from diffuse large B‐cell lymphoma (DLBCL). While in children BL and DLBCL types probably do not differ clinically, and the differential diagnosis between BL and DLBCL may theoretically appear clear‐cut, in adults daily practice shows the existence of cases that have morphological features, immunophenotypic and cytogenetics intermediate between DLBCL and BL, and cannot be classified with certainty in these categories. Distinguishing between BL and DLBCL is critical, as the two diseases require different management. This review summarizes the current practical approach, including the use of a large panel of antibodies, and cytogenetic and molecular diagnostic techniques, to distinguish between BL, DLBCL and the provisional category of “B‐cell lymphoma, unclassificable, with features intermediate between diffuse large B‐cell lymphoma and Burkitt lymphoma”, now listed in the updated WHO classification. Copyright © 2009 John Wiley & Sons, Ltd.     

Natural killer cell lymphoma/leukemia: pathology and treatment

Malignancies arising from cells of putative natural killer (NK) cell origin have increasingly been recognized as distinct clinicopathological entities. These malignancies are marked by tumour cells with NK cell characteristics, including the immunophenotype of CD2⁺, surface CD3⁻, cytoplasmic CD3ϵ+, CD7±, and CD56+, and the genotype of germline T cell receptor gene. A consistent association with monoclonal Epstein–Barr virus infection in the tumour cell has been observed. These tumours are now regarded as putative NK cell lymphoma/leukemia. Pathologically, tumour cells show variable cytological appearances, with frequent angiocentricity and angioinvasion, associated with zonal necrosis. Clinically, most cases occur in the nasal area and upper aerodigestive tract. However, occurrence in non-nasal sites such as the skin, gastrointestinal tract and testis is also observed. A particularly aggressive form of NK lymphoma/leukemia presents fulminantly as disseminated disease sometimes with a leukemic phase. All types of NK lymphoma/leukemia have an extremely poor prognosis with a median survival of less than a year. New modalities of treatment, including the use of high dose chemotherapy and stem cell rescue may be needed to improve treatment outcome. © 1997 John Wiley & Sons, Ltd.     

Heat shock protein 90 inhibitor NVP‐AUY922 exerts potent activity against adult T‐cell leukemia–lymphoma cells

Adult T‐cell leukemia–lymphoma (ATL), an aggressive neoplasm etiologically associated with HTLV‐1, is a chemoresistant malignancy. Heat shock protein 90 (HSP90) is involved in folding and functions as a chaperone for multiple client proteins, many of which are important in tumorigenesis. In this study, we examined NVP‐AUY922 (AUY922), a second generation isoxazole‐based non‐geldanamycin HSP90 inhibitor, and confirmed its effects on survival of ATL‐related cell lines. Analysis using FACS revealed that AUY922 induced cell‐cycle arrest and apoptosis; it also inhibited the growth of primary ATL cells, but not of normal PBMCs. AUY922 caused strong upregulation of HSP70, a surrogate marker of HSP90 inhibition, and a dose‐dependent decrease in HSP90 client proteins associated with cell survival, proliferation, and cell cycle in the G₁ phase, including phospho‐Akt, Akt, IKKα, IKKβ, IKKγ, Cdk4, Cdk6, and survivin. Interestingly, AUY922 induced downregulation of the proviral integration site for Moloney murine leukemia virus (PIM) in ATL cells. The PIM family (PIM‐1, ‐2, ‐3) is made up of oncogenes that encode a serine/threonine protein kinase family. As PIM kinases have multiple functions involved in cell proliferation, survival, differentiation, apoptosis, and tumorigenesis, their downregulation could play an important role in AUY922‐induced death of ATL cells. In fact, SGI‐1776, a pan‐PIM kinase inhibitor, successfully inhibited the growth of primary ATL cells as well as ATL‐related cell lines. Our findings suggest that AUY922 is an effective therapeutic agent for ATL, and PIM kinases may be a novel therapeutic target.     

Analysis of human leukemia/lymphoma cell lines with monoclonal antibodies BA-1, BA-2 and BA-3

A panel of monoclonal antibodies (BA-1, BA-2 and BA-3) were made against the pre-B acute lymphoblastic leukemia (ALL) cell line NALM-6. BA-3 binds to the 100,000 mol. wt common ALL antigen (gp100/CALLA), BA-2 binds to a 24,000 mol. wt (p24) cell surface structure and BA-1 binds to a currently undefined antigen. These antibodies were analysed for their reactivity with 67 human leukemia/lymphoma cell lines. The cell lines studied included T ALL, non-T ALL. surface immunoglobulin⁺ leukemias/lymphomas, and myeloid/monocytoid leukemias. The results indicate that all three antibodies react primarily (but not exclusively) with malignant cells early in B cell development. This pattern of reactivity was similar to previous results obtained with fresh, non-cultured malignant cells. BA-1, BA-2 and BA-3 are useful tools for analysing the developmental options of normal lymphoid cells and for “cleaning up” leukemia/lymphoma cells in selected cases of autologous bone marrow transplantation.     

Subclonal evolution of a classical Hodgkin lymphoma from a germinal center B‐cell‐derived mantle cell lymphoma

Composite lymphomas (CL) represent the occurrence of two distinct lymphomas in the same patient. Often, CL share a common cellular origin, thus representing a unique model to investigate the multistep genetic path leading to lymphomagenesis in general and to the specific development of each distinct lymphoma component in particular. Here, we present the molecular analysis of a case consisting of an unusual Hodgkin lymphoma (HL) and a mantle cell lymphoma (MCL), intimately admixed within one another in lymph nodes and bone marrow yet phenotypically distinct, in a patient who first presented with splenic/leukemic MCL two years earlier. MCL and Hodgkin and Reed/Sternberg (HRS) cells harbored identical immunoglobulin (Ig) V_H gene rearrangements with shared somatic mutations, proving their common clonal origin from a (post‐)germinal center (GC) B cell. This also demonstrates the (post‐)GC origin of MCL with mutated IgV genes. Both lymphomas carried the same CCND1/IGH translocation and, unexpectedly for HL, expressed cyclin D1 and OCT2. Thus, HRS cells are able to preserve IGH locus activity (otherwise usually silenced in HL) to promote expression of an oncogene translocated into this locus. Both lymphoma populations further showed an identical TP53 function‐impairing mutation, and later acquired a TP53 heterozygous deletion independently from one another (convergent evolution). The surprisingly close genetic relationship of the lymphomas, together with their histological intermingling and the clinical history of the patient, suggests subclonal evolution of HL from MCL as a plausible pathway in alternative to that so far described in CL, i.e. separate development from a common precursor.     

Check your cultures! A list of cross‐contaminated or misidentified cell lines

Continuous cell lines consist of cultured cells derived from a specific donor and tissue of origin that have acquired the ability to proliferate indefinitely. These cell lines are well‐recognized models for the study of health and disease, particularly for cancer. However, there are cautions to be aware of when using continuous cell lines, including the possibility of contamination, in which a foreign cell line or microorganism is introduced without the handler's knowledge. Cross‐contamination, in which the contaminant is another cell line, was first recognized in the 1950s but, disturbingly, remains a serious issue today. Many cell lines become cross‐contaminated early, so that subsequent experimental work has been performed only on the contaminant, masquerading under a different name. What can be done in response—how can a researcher know if their own cell lines are cross‐contaminated? Two practical responses are suggested here. First, it is important to check the literature, looking for previous work on cross‐contamination. Some reports may be difficult to find and to make these more accessible, we have compiled a list of known cross‐contaminated cell lines. The list currently contains 360 cell lines, drawn from 68 references. Most contaminants arise within the same species, with HeLa still the most frequently encountered (29%, 106/360) among human cell lines, but interspecies contaminants account for a small but substantial minority of cases (9%, 33/360). Second, even if there are no previous publications on cross‐contamination for that cell line, it is essential to check the sample itself by performing authentication testing.     

Simultaneous presentation of hairy cell leukemia and follicular small cleaved cell lymphoma in a patient with previous diagnosis of renal cell carcinoma

Hairy cell leukemia is a lymphoproliferative disorder of the B lymphoid system that is associated with an increased incidence of second malignancies. Most of these second neoplasma have been solid tumours and few reports of lymphoid malignancies exist. We report here a case of simultaneous presentation of hairy cell leukemia diagnosed in the spleen of a patient under therapy for follicular lymphoma who had an antecendent history of renal cell carcinoma. The hairy cell leukemia and the follicular lymphoma were studied by means of molecular techniques and they were found to contain two different clonal B cell proliferations. This suggests an independent origin of these two B cell neoplasms. As far as we know, this is the first report of the coexistence of hairy cell leukemia and follicular lymphoma.     

Distribution of androgen and estrogen receptors among lymphoid and haemopoietic cell lines

Estrogen receptors (ER) and androgen receptors (AR) were determined in a series of 23 leukemia or lymphoma cell lines including 8 T-cell lines, 12 B-cell lines, and 3 non lymphoid cell lines. The phenotypic characterization of these cells by currently available immunological markers provides an estimate of their stage of differentiation. The result indicate that none of the investigated cell lines bear simultaneously ER and AR. Four were found to bear ER: U266, RPMI 8226, HL60, IARC/310/LT2, and four to express AR: RAJI, IARC/301/LTI, U937, REH6. The presence of cytosolic receptors was always associated with that of nuclear receptors. The expression of either ER or AR is restricted to discrete maturation stages of different haemopoietic cell lineages. Thus AR were found among the most immature lines of the T, B or monocytic lineage but they could be detected neither in the promyelocytic line HL60, nor in the pluripotential K562. The present results are in keeping with the demonstration of AR in some leukaemic blasts or in non Hodgkin's lymphomas. In contrast with AR, ER are present in two myeloma cell lines, in the promyelocytic cell line, HL60 and in a T-cell line bearing the phenotype of mature suppressor/cytotoxic T cells.     

Frontline treatment of diffuse large B‐cell lymphoma: Beyond R‐CHOP

Although the majority of patients with diffuse large B‐cell lymphoma (DLBCL) can be cured with the standard immunochemotherapy R‐CHOP, one‐third of them relapses with a dismal outcome in most cases. In the recent years, remarkable advances have been achieved based on the discovery of molecular genetics in DLBCL. In addition to the major cell‐of‐origin designations of germinal center B‐cell and activated B‐cell subtypes, next‐generation sequencing has unveiled the remarkable complexity of DLBCL and identified potential molecular targets for tailored therapies. Despite these findings, the current standard of care for DLBCL patients is still R‐CHOP, and optimization of frontline therapy remains an important goal. In this review, we summarize recent updates on the evolution of frontline therapies for DLBCL.     

Successful treatment of extranodal Hodgkin's lymphoma in a patient with longstanding hairy cell leukemia

Purine analogs, particularly pentostatin and cladribine, are highly effective in hairy cell leukemia (HCL). Both of these drugs induce responses in approximately 80 - 95% of patients. However, it is not yet determined if treatment with these drugs can induce second malignancies. Hodgkin's lymphoma is very rare as a second malignancy and there are only 3 reported cases concerning the association of this lymphoma with HCL. We describe a patient with longstanding HCL in complete remission after cladribine, in whom extranodal Hodgkin's lymphoma appeared 8 years after the diagnosis of HCL. Magnetic resonance imaging revealed diffuse intra-osseal neoplastic infiltration of the corpora of the whole spinal column and extra-osseal propagation from the fifth thoracic vertebra into the spinal canal with spinal cord compression. Histological and immunohistochemical analysis of the extradural tumor, which was completely excised, disclosed nodular sclerosis Hodgkin's lymphoma with typical Reed - Sternberg cells that were positive for CD30, CD15, bcl-6, Ki67, p53, EBV LPM-1 and IgG, and negative for CD45, CD20, DBA44, kappa, lambda light chains and IgM. In addition, immunohistochemical analysis of the bone marrow in 1999 showed infiltration with positivity for IgM and negative for kappa light chains and IgG. These findings (expression of different immunoglobulins and light chains on the cells) suggest an independent origin of these 2 B-cell neoplasms. After neurosurgery the patient received 6 courses of the MP-ABVD protocol and achieved a complete remission, which has lasted 16 months thus far.