The 2017 WHO update on mature T- and natural killer (NK) cell neoplasms

Over the last decade, there has been a significant body of information regarding the biology of the lymphoid neoplasms. This clearly supports the need for updating the 2008 WHO (World Health Organization) classification of haematopoietic and lymphoid tumours. The 2017 WHO classification is not a new edition but an update and revision of the 4th edition. New provisional entities but not new definitive entities are included, and novel molecular data in most of the entities and changes in the nomenclature in few of them have been incorporated. In the context of the mature T- and NK-cell neoplasms, the most relevant updates concern to: 1-dysregulation of the JAK/STAT pathway due to gene mutations which are common to various aggressive and indolent neoplasms; 2-incorporation of new molecular players that are relevant to the pathogenesis of these neoplasms and/or have prognostic implications; 3-inclusion of new provisional entities within the subgroups of anaplastic, primarily intestinal and cutaneous lymphomas such as breast implant-associated anaplastic large cell lymphoma, indolent T-cell lymphoproliferative disorder of the gastrointestinal tract and primary cutaneous acral CD8⁺ T-cell lymphoma; 4-identification of poor prognostic subtypes of peripheral T-cell lymphomas not otherwise specified (PTCL, NOS) characterized by overexpression of certain genes and of a subgroup PTCL, NOS with a T follicular phenotype that now is included together with angioimmunoblastic T-cell lymphoma under the umbrella of lymphomas with a T follicular helper phenotype; and 5-refinement on the designation and definition of already established entities. A review of the major changes will be outlined.

Over 30% of patients with splenic marginal zone lymphoma express the same immunoglobulin heavy variable gene: ontogenetic implications

We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele (*)04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2(*)04 peaked at 31%. The IGHV1-2(*)04 rearrangements carried significantly longer complementarity-determining region-3 (CDR3) than all other cases and showed biased IGHD gene usage, leading to CDR3s with common motifs. The great majority of analyzed rearrangements (299/345, 86.7%) carried IGHV genes with some impact of somatic hypermutation, from minimal to pronounced. Noticeably, 75/79 (95%) IGHV1-2(*)04 rearrangements were mutated; however, they mostly (56/75 cases; 74.6%) carried few mutations (97-99.9% germline identity) of conservative nature and restricted distribution. These distinctive features of the IG receptors indicate selection by (super)antigenic element(s) in the pathogenesis of SMZL. Furthermore, they raise the possibility that certain SMZL subtypes could derive from progenitor populations adapted to particular antigenic challenges through selection of VH domain specificities, in particular the IGHV1-2(*)04 allele.

CD52 expression in T-cell large granular lymphocyte leukemia – Implications for treatment with alemtuzumab

Few reports on the successful treatment of T-cell large granular lymphocyte (LGL) leukemia with the humanized anti-CD52 monoclonal antibody alemtuzumab are emerging in the literature. The expression of CD52 by LGLs has not been previously investigated. Using semi-quantitative 2- and 3-color flow cytometry, we documented the expression of CD52 in 100% of abnormal cells in T-cell LGL leukemia (n = 11) and natural killer (NK) cell LGL leukemia (n = 2), and showed no significant difference in CD52 expression between T-cell prolymphocytic leukemia (PLL) and T-cell LGL leukemia. Higher CD52 expression has been noted in responders to alemtuzumab in T-cell PLL and in chronic lymphocytic leukemia (CLL), a B-cell disorder. The strong and consistent expression of CD52 shown here highlights the potential role of alemtuzumab in the treatment of refractory T-cell LGL leukemia and possibly aggressive NK cell leukemia.

Fludarabine, Cyclophosphamide and Mitoxantrone in Relapsed or Refractory Chronic Lymphocytic Leukemia and Low Grade Non-Hodgkin's Lymphoma

A regimen combining fludarabine, cyclophosphamide and mitoxantrone (FCM) was used to treat 29 patients with relapsed or refractory chronic lymphocytic leukemia (CLL, N = 24) and low-grade non-Hodgkin's lymphoma (NHL, N = 5) based on evidence suggesting synergism between the 3 drugs. Patients were treated with mitoxantrone 5mg/m2 i.v. day 1 only, fludarabine 25 mg/m2 i.v. for 3 days or 24 mg/m2 orally for 5 days, cyclophosphamide 250 mg/m2 i.v. for 3 days or 150 mg/m2 orally for 5 days inclusive. Eighteen patients had previously received fludarabine and most were heavily pretreated with 40% having >2 prior treatments. A median number of 4 FCM courses (range of 1-9) were given. The response rate was 78.5%: 32% complete remission, 25% nodular partial remission, 21.5%, partial remission. Median duration of response was 19 months and median survival was 42 months. Sixteen patients (57%) developed neutropenia to < 0.5 x 10(9)/l and 12 (43%) infectious complications. Four patients developed large cell lymphoma (Richter's syndrome) and 2 acute myeloid leukemia. FCM is a useful combination for relapsed or refractory CLL and low grade NHL with high response rates and long duration of response. The role of FCM as first line therapy deserves study as well as its combination with the monoclonal antibody Rituximab.

The Leukemic Presentation of Mantle-cell Lymphoma: Disease Features and Prognostic Factors in 58 Patients

Mantle-cell lymphoma (MCL) is a B-cell malignancy with distinct molecular genetics and pathological features. Peripheral blood involvement has been reported with variable frequency, but information on the natural history of cases presenting with leukemia is lacking. This study aimed to determine the clinical and prognostic features of such cases. We studied clinical features, tumor characteristics, prognostic factors and outcome in 58 patients with leukemic presentation of MCL. Diagnosis was based on morphology, immunophenotype, presence of t(11;14), histology and cyclin D1 expression. The median age was 62 years and male:female 2.4:1. Presenting features included splenomegaly (74%), lymphadenopathy (45%), hepatomegaly (17%) and, in a minority, gastro-intestinal involvement or involvement of Waldeyer's ring; 10% had lymphocytosis alone. Six patients developed central nervous system disease. Median lymphocyte count was 58 x 10(9)/l, 55% had anemia and 17% had thrombocytopenia. Morphology of peripheral blood showed small-cell MCL in 15% of cases, typical MCL in 46% and blastoid MCL in 39%. Immunological markers showed a typical phenotype (CD5+ CD23 -) in 68%, and atypical phenotypes, CD5- CD23- in 17% or CD5+ CD23+ in 15%. CLL scores were 0, 1 or 2 in 96%. Median overall survival was 36 months. Good response to first-line treatment (P = 0.0008) and splenomegaly (P = 0.03) were favorable prognostic factors, while other features including morphology and CD38 expression had no impact on survival or treatment response. This analysis demonstrates that except for splenomegaly, survival of MCL patients presenting with leukemia is not significantly influenced by clinical or tumor characteristics. Splenectomy is a useful treatment option in this group of patients.

Splenic marginal zone lymphoma proposals for a revision of diagnostic, staging and therapeutic criteria

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are proposed for diagnosis, differential diagnosis, staging, prognostic factors, treatment and response criteria. The guidelines proposed here are intended to contribute to the standardization of the diagnosis and treatment of these patients, and should facilitate the future development of clinical trials that could define more precisely predictive markers for histological progression or lack of response, and evaluate new drugs or treatments.

Adult T-cell leukaemia/lymphoma

Adult T-cell leukaemia/lymphoma (ATLL) is a mature T-cell neoplasm of post-thymic lymphocytes aetiologically linked to the human T-cell lymphotropic virus, HTLV-I, and with a distinct geographical distribution. The disease manifests with leukaemia in greater than two thirds of patients, while the remaining patients have a lymphomatous form. According to the disease manifestations, various forms which differ in clinical course and prognosis have been recognised: acute, chronic, smouldering and lymphoma. Organomegaly, skin involvement, circulating atypical lymphocytes ("flower" cells) with a CD4+ CD25+ phenotype and hypercalcaemia are the most common disease features. The diagnosis should be based on a constellation of clinical features and laboratory investigations. The latter comprise: lymphocyte morphology, immunophenotype, histology of the tissues affected in the pure lymphoma forms and serology or DNA analysis for HTLV-I. The differential diagnosis of ATLL includes other mature T-cell neoplasms such as T-cell prolymphocytic leukaemia (T-PLL), Sézary syndrome (SS), peripheral T-cell lymphomas and occasionally healthy carriers of the virus or Hodgkin disease. The clinical course is aggressive with a median survival of less than 12 months in the acute and lymphoma forms. Despite major advances in understanding the pathogenesis of the disease, management of these patients remains a challenge for clinicians as they do not respond or achieve only transient responses to therapies used in high-grade lymphomas. The use of antiretroviral agents such as zidovudine in combination with interferon-alpha, with or without concomitant chemotherapy, has shown activity in this disease with improvement in survival and response rate. Consolidation with high dose therapy and autologous or allogeneic stem-cell transplantation should be considered in young patients.

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial

BACKGROUND

Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine.

METHODS

777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610.

FINDINGS

There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival.

INTERPRETATION

Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

Microsatellite instability indicative of defects in the major mismatch repair genes is rare in patients with B-cell chronic lymphocytic leukemia: Evaluation with disease stage and family history

A possible role for DNA mismatch repair defects and microsatellite instability (MSI) in the pathogenesis of a number of B-cell lymphoproliferative disorders has recently been debated. To gain further insight into the impact of MSI on B-CLL, we evaluated samples from a series of 982 patients using the mono-satellite markers BAT25 and BAT26, which are highly sensitive in demonstrating classical mismatch repair (MMR) deficiency. Only 1% of cases displayed MSI and this was not correlated with stage of disease or family history of B-CLL. A sub-polymorphic germline variant of BAT25 was identified in one familial case, which was also detected in the patient's affected brother. In conclusion, our study demonstrates that MSI does not have a prominent role in the pathogenesis of B-CLL.

Characteristic appearances of the bone marrow in T-cell large granular lymphocyte leukaemia

AIMS

To augment the limited literature on bone marrow (BM) appearances in T-cell large granular lymphocyte (LGL) leukaemia and to identify a histological signature to aid in diagnosis of this condition.

METHODS AND RESULTS

A descriptive analysis of the histology of the BM in T-cell LGL leukaemia was performed (n = 38). Antibodies against CD3, CD4, CD5, CD8, CD16, CD56, CD57 and CD20 or CD79a were employed. Antibodies against CD68 (macrophages) and CD34 (sinusoids) were also included. BM was normocellular or hypercellular in the majority of cases, with interstitial lymphoid infiltration in 97%. Lymphoid nodules were present in 55% and intrasinusoidal permeation in 58%. Apoptotic figures and haemosiderin deposition were common. All cases showed trilinear haematopoiesis with normal or increased megakaryopoiesis and erythropoiesis, but normal/reduced myelopoiesis. Reticulin was increased (Grade II-III). Immunohistochemistry revealed interstitial infiltration in all cases and helped to identify lymphoid nodules in two-thirds of cases. Preferential localization of CD8+ T lymphocytes to the interstitium and CD4+ T lymphocytes to the periphery of CD20+ B-cell nodules was seen in almost 90% of cases.

CONCLUSIONS

Nodules with non-clonal B-cell centres surrounded by CD4+ cells, with interstitial CD8+ cells, are a characteristic finding in T-cell LGL leukaemia and may represent a histological signature for this condition.

Cytogenetic abnormalities additional to t(11;14) correlate with clinical features in leukaemic presentation of mantle cell lymphoma, and may influence prognosis: a study of 60 cases by FISH

Mantle cell lymphoma (MCL), characterised by t(11;14)(q13;q32), has a poor prognosis. Many cases have additional cytogenetic abnormalities, and often have a complex karyotype. Fluorescence in situ hybridisation (FISH) was used to study 60 cases with leukaemic presentation of MCL, to determine the frequency, clinical correlations and prognostic impact of a panel of molecular cytogenetic abnormalities: 17p13 (TP53 locus), 13q14, 12 p11.1-q11 (centromere), 6q21 and 11q23. CD38 expression, of prognostic value in chronic lymphocytic leukaemia (CLL), was also studied, and correlations with clinical and cytogenetic abnormalities sought. Eighty per cent of cases had at least one abnormality in addition to t(11;14). Deletions at 17p13 (TP53) and 13q14 were most frequent and involved the majority of the leukaemic clone. Cases with TP53 deletion were more likely to have splenomegaly and marked leucocytosis (>30 x 10(9)/l), and less likely to have lymphadenopathy than those without deletion. Deletions at 11q23 and 6q21 were associated with extranodal disease. 13q14 and 11q23 deletions showed a trend towards worse prognosis by univariate analysis. In multivariate analysis, deletions at 13q14 and 6q21 were independent predictors of poor outcome. Deletion at 17p13 did not show prognostic impact in this series. CD38, positive in two-thirds of cases, was associated with male gender and nodal disease but not with any cytogenetic abnormality, or with survival.

Gemcitabine, cisplatin and methylprednisolone (GEM-P) in patients with T-cell lymphoma: Results from The Royal Marsden Hospital

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Background: There is a need for novel, effective therapies for T-cell non-Hodgkin’s lymphoma (NHL). The combination of gemcitabine, cisplatin and methylprednisolone (GEM-P) has shown activity in patients (pts) with relapsed Hodgkin’s disease and NHL (Chau I et al. Br J Haematol 2003, Baetz T et al. Ann Oncol 2003). We report a single institution retrospective analysis of GEM-P for pts with T-cell NHL. Methods: Sixteen pts with T-cell NHL treated at the Royal Marsden Hospital between June 2001 and March 2005 with GEM-P (gemcitabine 1 g/m2 D1, 8, 15; cisplatin 100 mg/m2 D15; methylprednisolone 1 g D1–5, repeated every 28D) were identified. Results: 16 pts (9 males and 7 females) were analysed. Histological subtypes were: angioimmunoblastic (n = 5), T-cell enteropathy (n = 2), NK/T cell nasal-type (n = 2), T-cell anaplastic (n = 3) and peripheral T-cell unspecified (n = 3). Median age was 55 years (range: 18–71 years), 69% had IPI-score ≥ 2 and 69% had stage III/IV disease. 15 /16 pts were pre-treated: median number of prior treatments: 1 (range: 0–4). At the start of GEM-P treatment pts presented with: primary refractory disease (n = 3), 1st relapse (n = 6), 1st relapse refractory (n = 3), 2nd relapse (n = 2) and 4th relapse (n = 1). Median time from diagnosis of T-cell NHL to start of GEM-P was 8.9 months(m) and median number of cycles given was 3 (range: 1–6). Of 16 evaluable patients, 3 pts (19 %) achieved complete remission (CR), 8 pts (50 %) achieved partial remission (PR), (ORR= 69%; CI-95% 41.4–89.0) and 5 pts (31%) progressed while on GEM-P. One pt received high dose chemotherapy (melphalan/etoposide) after CR to GEM-P. After a median follow up of 17.4m the mean progression free survival (PFS) was 9m (range 1.15–37.5). The median overall survival (OS) has not been reached and the survival probability at 1 year was 68.2% (95% CI: 40–85). The main grade 3/4 toxicities were myelosuppression (leucopenia 62%, neutropenia 62% and anaemia 12%) and required granulocyte colony stimulating factor (GCSF) in 3 pts with neutropenic sepsis and in 1 pt with neutropenia. Conclusion: GEM-P has encouraging efficacy with an acceptable toxicity profile in pts with previously treated T-cell NHL.

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