Second Malignancies and Richter's Syndrome in Patients with Chronic Lymphocytic Leukemia

Cutaneous manifestations of B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a malignant lymphoproliferative disease characterized by the accumulation of immature monoclonal B lymphocytes in blood cells, bone marrow, spleen and lymph nodes. This is the most common type of leukemia among the Caucasoid race. When CLL skin lesions occur in about 25% of patients, they are extremely diverse. These lesions can be divided into specific, including infiltration of the skin by leukemic cells and the skin form of Richter's syndrome, secondary skin tumors, nonspecific lesions and associated skin diseases.Leukemic infiltration of the skin in patients with leukemia is called specific skin lesions (SSL). Many authors associate the unfavorable prognosis with the transformation of CLL with specific infiltration of the skin into Richter syndrome, as well as the appearance of SSL before the diagnosis of CLL. The risk of developing various cancer pathologies in patients with CLL is three times higher than in healthy people identical in sex and age. It was found that the risk of skin cancer in these patients is eight times higher than in the healthy population. The most common secondary skin tumors in CLL are basal-cell carcinoma, squamous-cell carcinoma, melanoma, and Merkel tumor.Nonspecific skin changes are extremely diverse and occur in patients with CLL in 30-50% of cases. The most common secondary changes in the skin in CLL are those of infectious nature. There are also increased reactions to insect bites, generalized itching, exfoliative erythroderma, nodular erythema, paraneoplastic pemphigoid, bullous pemphigoid, drug eruption. Concomitant dermatoses in these patients are more severe and often torpid to the previously conducted therapy. There is no doubt that together with the clarification of the etiology and pathogenesis of CLL, particular issues related to the study of clinical and morphological changes in individual organs and systems, in particular the skin, formed at various stages of the development of this disease should be studied in detail. This can not only expand and clarify our understanding of this pathology, but also can help to clarify the essence of the disease.

Immunochemotherapy for Richter syndrome: current insights

Richter syndrome (RS) is recognized as the development of a secondary and aggressive lymphoma during the clinical course of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Most of such histological transformations are from RS to diffuse large B-cell lymphoma (DLBCL-RS, 90%) and Hodgkin’s lymphoma (HL-RS, 10%). Histopathological examination is a prerequisite for diagnosis. It is crucial to assess the relationship between the RS clone and the underlying CLL/SLL because clonally related DLBCL-RS has a poor outcome, while clonally unrelated cases have a prognosis similar to de novo DLBCL. An anti-CD20 antibody-based immunochemotherapy is hitherto the frontline treatment of choice for DLBCL-RS; nonetheless, the results are unsatisfactory. Allogeneic stem cell transplantation should be offered to younger and fit patients as a consolidative treatment; however, the majority of the patients may not be qualified for this procedure. The HL-RS transformation has better outcomes than those of DLBCL-RS and can effectively be treated by the adriamycin, bleomycin, vinblastine, and dacarbazine regimen. Although novel agents are currently being investigated for RS, immunochemotherapy nevertheless remains a standard treatment for DLBCL-RS.

A case report of extranodal NK/T-cell lymphoma in patient with chronic lymphocytic leukemia

RATIONALE

Chronic lymphocytic leukemia often results in secondary tumors, the most common being large B cell lymphoma known as Richter syndrome, followed by extranodal NK/T-cell lymphoma (nasal type) is extremely rare.

PATIENT CONCERNS

A chronic lymphocytic leukemia patient presented with nasal congestion.

DIAGNOSES

Nasal endoscopy identified a left nasal mass, and the pathology suggested extranodal NK/T-cell lymphoma (nasal type).

INTERVENTIONS

The patient received a course of chemotherapy.

OUTCOMES

Pneumonia and coagulopathy occurred after chemotherapy, and the patient died shortly thereafter.

LESSONS

It is essential to recognize the transformation of disease earlier in chronic lymphoblastic leukemia patient.

Second lung malignancy and Richter syndrome in chronic lymphocytic leukemia: case report and literature review

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most frequent lymphoproliferative disease. Transformation into Richter disease and occurrence of second malignancies involving the lungs are rare complications. The hallmarks of any thoracic involvement are still unknown.

CASE PRESENTATION

We report a case of a 56-year-old male patient, with history of tobacco smoking, who presented with recurrent hemoptysis, fatigue and weight loss. Physical examination was normal except a slightly enlarged supraclavicular lymph node. Chest x-ray revealed a mediastinal widening due to enlarged paratracheal nodes and a left parahilar infiltrate. Blood tests showed a hyperlymphocytosis and a biological inflammatory syndrome. CT scan showed bilateral mediastinal and axillary lymphadenopathy, as well as left supraclavicular lymphadenopathy, with a left upper lobe alveolar attenuation and a solitary contralateral pulmonary nodule. Examination of Virchow's node and bone marrow biopsies confirmed metastasis of a pulmonary adenocarcinoma, as well as chronic lymphocytic leukemia with Richter's transformation. The clinical course was unfavorable since the first days of therapy as the patient passed away in a matter of a few days.

CONCLUSIONS

Steady surveillance of CLL patients and systematic screening for second solid tumors, particularly lung cancer, and Richter's transformation seem to be relevant more than ever. Early diagnosis might help us understand the pathways leading to these complications and adapt therapy.

Update of the Grupo Español de Leucemia Linfocítica Crónica clinical guidelines of the management of chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVE

The broad therapeutic arsenal and the biological heterogeneity of patients with chronic lymphocytic leukemia (CLL) makes it difficult to standardize treatment for CLL patients with specific clinical settings in routine clinical practice. These considerations prompted us to elaborate the present consensus document, which constitutes an update of the previous version published in 2013, mainly focusing on novel treatment strategies that have been developed over last 5 years, namely B-cell receptor inhibitors (ibrutinib and idelalisib), anti-CD20 monoclonal antibodies (ofatumumab and obinutuzumab), and Bcl-2 inhibitors (venetoclax).

MATERIAL AND METHODS

A group of experts from the Spanish Chronic Lymphocytic Leukemia Group reviewed all published literature from January 2010 to January 2016, in order to provide recommendations based on clinical evidence. For those areas without strong scientific evidence, the panel of experts established consensus criteria based on their clinical experience.

RESULTS

The project has resulted in several practical recommendations that will facilitate the diagnosis, treatment, and follow-up of patients with CLL.

CONCLUSIONS

There are many controversial issues in the management of CLL with no appropriate studies for making consensus recommendations.

Diagnosis and treatment of chronic lymphocytic leukemia: recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia is characterized by clonal proliferation and progressive accumulation of B-cell lymphocytes that typically express CD19⁺, CD5⁺ and CD23⁺. The lymphocytes usually infiltrate the bone marrow, peripheral blood, lymph nodes, and spleen. The diagnosis is established by immunophenotyping circulating B-lymphocytes, and prognosis is defined by two staging systems (Rai and Binet) established by physical examination and blood counts, as well as by several biological and genetic markers. In this update, we present the recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia for the diagnosis and treatment of chronic lymphocytic leukemia. The following recommendations are based on an extensive literature review with the aim of contributing to more uniform patient care in Brazil and possibly in other countries with a similar social–economic profile.

CLL/SLL with initial presentation as a longstanding cutaneous plaque: a rare case

While chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is the most common leukemia in the western world, it uncommonly initially presents as a cutaneous lesion. When it does, it is often found incidentally in the context of another distinct lesion. We present a case of CLL/SLL that initially presented as a solitary nodular erythematous plaque on the left flank of a healthy 60-year-old man without lymphadenopathy or constitutional symptoms. The lesion had been present for many years, but had recently begun to grow and become pruritic and painful. Excisional biopsy revealed a large nodular aggregate of variably sized CD20(dim), CD5(+), CD23(+), BCL-2(+) atypical lymphocytes in the dermis without epidermotropism. The lymphocytes were negative for BCL-1/cyclinD1, BCL-6, and CD10, and no other background lesion was identified. This constellation of biopsy findings was consistent with CLL/SLL. This case emphasizes the potential for involvement by CLL/SLL in the cutaneous biopsies of otherwise asymptomatic patients.

Three-fold higher frequency of circulating chronic lymphocytic leukemia-like B-cell clones in patients with Ph-Myeloproliferative neoplasms

Philadelphia chromosome-negative Myeloproliferative neoplasms (Ph-MPN) are accompanied by a markedly increased risk for development of chronic lymphocytic leukemia (CLL) compared to the general population. However, the pattern of onset and the biological characteristics of CLL in patients with coexistent Ph-MPN are highly heterogeneous rendering questionable if the above association reflects a causal relationship between the two disorders or merely represents a random event. By analyzing 82 patients with Ph-MPN and 100 age-matched healthy individuals we demonstrate that MPN patients have an almost threefold higher prevalence of, typically low-count, CLL-like monoclonal B lymphocytosis (MBL) compared to normal adults. The clone size remained unaltered during the disease course and unaffected by the administration of hydroxycarbamide, whereas no patient with Ph-MPN/MBL progressed to CLL during a median follow up of 4 years. Monoclonal B cells in Ph-MPN/MBL patients and normal individuals and in four more patients with coexistence of overt CLL and MPN displayed heterogeneous biological characteristics, while the JAK2V617F mutation was absent in isolated lymphocytes from Ph-MPN patients with coexistence of CLL. Despite its clinical and biological variability, the increased incidence of MBL in Ph-MPN patients along with the one reported for CLL further enforces the notion of a shared pathophysiology among the two malignancies via a common genetic link and/or microenviromental interactions.

Melanoma and non-melanoma skin cancers in hairy cell leukaemia: a Surveillance, Epidemiology and End Results population analysis and the 30-year experience at Memorial Sloan Kettering Cancer Center

Few studies have examined melanoma and non-melanoma skin cancer (NMSC) incidence rates after a diagnosis of hairy cell leukaemia (HCL). We assessed 267 HCL patients treated at Memorial Sloan Kettering Cancer Center (MSKCC) and Surveillance, Epidemiology and End Results (SEER) data for melanoma and NMSC incidence rates after HCL. Incidence data from MSKCC patients demonstrated a 10-year combined melanoma and NMSC skin cancer rate of 11·3%, melanoma 4·4% and NMSC 6·9%. Molecular analysis of skin cancers from MSKCC patients revealed activating RAS mutations in 3/9 patients, including one patient with melanoma. Of 4750 SEER patients with HCL, 55 (1·2%) had a subsequent diagnosis of melanoma. Standardized incidence ratios (SIRs) did not show that melanoma was more common in HCL patients versus the general population (SIR 1·3, 95% CI 0·78-2·03). Analysis of SEER HCL patients diagnosed before and after 1990 (approximately before and after purine analogue therapy was introduced) showed no evidence of an increased incidence after 1990. A better understanding of any potential association between HCL and skin cancer is highly relevant given ongoing trials using BRAF inhibitors, such as vemurafenib, for relapsed HCL, as RAS-mutant skin cancers could be paradoxically activated in these patients.

[National guidelines for the management of patients with chronic lymphocytic leukemia. Sociedad Espan˜ola de Hematologı´a y Hemoterapia and Grupo Espan˜ol de Leucemia Linfocı´tica Cro´ nica]

Chronic lymphocytic leukemia is the most common chronic lymphoproliferative disorder in Spain. The clinical management of this entity varies widely. Currently, in Spain, there are no national consensus guidelines, such as those published in other countries, to guide the diagnosis and treatment of this malignancy and the use of prognostic scores. This article reviews the current scientific literature and addresses issues on the diagnosis of chronic lymphocytic leukemia, the spread of the disease, the presence of comorbidities, the classification of prognostic scores, the common treatment regimens stratified by risk factors, and the management of complications associated with both the disease and its treatment, as well as the various controversies related to this entity. This document was drafted with the collaboration of national experts and aims to establish practical guidelines with their corresponding levels of evidence and grades of recommendation to guide the diagnosis, treatment and follow-up of patients with chronic lymphocytic leukemia.

The impact of initial fludarabine therapy on transformation to Richter syndrome or prolymphocytic leukemia in patients with chronic lymphocytic leukemia: analysis of an intergroup trial (CALGB 9011)

The impact of initial fludarabine therapy on transformation to Richter syndrome (RS) or prolymphocytic leukemia (PLL) in patients with chronic lymphocytic leukemia (CLL) is uncertain. We studied the outcomes of 521 patients with CLL who were randomized to initial fludarabine (F), chlorambucil (C) or F + C therapy on an intergroup trial (CALGB 9011). RS developed in 34 (7%) patients and PLL in 10 (2%). RS and PLL occurred in 14 (7%) and three (2%) of 188 patients randomized to F; nine (5%) and four (2%) of 191 patients treated with C; and 11 (8%) and three (2%) of 142 receiving F + C, respectively. Four percent of the 206 patients with Rai stage III/IV developed PLL, compared to only 1% of the 315 patients with Rai stage I/II (p = 0.02). Initial fludarabine therapy in patients with CLL did not impact transformation to RS or PLL, nor were any other baseline characteristics predictive for such transformation in this series.

Multiple myeloma and its therapies: to what extent do they contribute to the increased incidence of second malignant neoplasms?

BACKGROUND

The high risk of another cancer once one has been diagnosed is well known. Furthermore, a clear association exists between the use of some cytotoxic agents and chemotherapy-induced malignancies.

METHODS

This review is set to explore the relationship between multiple myeloma, its modern therapies and the development of second cancers due to various genetic, immune, and environmental (including iatrogenic) factors. Most relevant publications were identified through the PubMed database and by reviewing the drug information released by the US Federal Drug Administration.

FINDINGS

Our comprehensive analysis identified several retrospective population studies, cohort group analyses and a number of case reports linking myeloma with other cancers in the world literature. A majority of these studies suggest that incidence of second solid and hematologic malignancies is significantly increased in patients with multiple myeloma and its precursor lesion, monoclonal gammopathy of unknown significance. In addition, incidence of second malignancies has been found increased in the family members of these individuals, especially in their first-degree relatives.

CONCLUSIONS

Analysis of the existing literature cohorts does not discriminate between the burden of second cancers in treated myeloma patients as opposed to the patients followed with the wait-and-watch approach. Notably, the rate of second malignant neoplasms in multiple myeloma may be further increased by certain myeloma therapies. These cancers include, for the most part, hematologic malignancies such as acute leukemias and certain lymphomas. While there is no question about the role of alkylating agents and topoisomerase II inhibitors in this regard, further research is necessary to determine whether the excess of second cancers represents a direct consequence of lenalidomide use.

Second cancer incidence and cancer mortality among chronic lymphocytic leukaemia patients: a population-based study

Background:

Patients with chronic lymphocytic leukaemia (CLL) are known to have increased risks of second cancer. The incidence of second cancers after CLL has not been reported in detail for Australia, a country with particularly high levels of ultraviolet radiation (UVR).

Methods:

The study cohort comprised of all people diagnosed with a primary CLL between 1983 and 2005 in Australia. Standardised incidence ratios (SIRs) and standardised mortality ratios (SMRs) were calculated using Australian population rates.

Results:

Overall, the risk of any second incident cancer was more than double that of the general population (SIR=2.17, 95% confidence interval (CI)=2.07, 2.27) and remained elevated for at least 9 years after CLL. Risks were increased for many cancers, particularly melanoma (SIR=7.74, 95% CI=6.85, 8.72). The risk of melanoma increased at younger ages, but was constant across >9 years of follow-up. Chronic lymphocytic leukaemia patients also had an increased risk of death because of melanoma (SMR=4.79, 95% CI=3.83, 5.90) and non-melanoma skin cancer (NMSC; SMR=17.0, 95% CI=14.4, 19.8), suggesting that these skin cancers may be more aggressive in CLL patients.

Conclusion:

We speculate that a shared risk factor, such as general immune suppression, modulated by UVR exposure may explain the increased risk of melanoma and NMSC in CLL patients.

Therapy-Related Myeloid Neoplasms in Chronic Lymphocytic Leukemia and Waldenstrom's Macroglobulinemia

Secondary myelodysplasia (MDS) and acute myeloid leukemia (AML) are frequent long term complications in Chronic Lymphocytic Leukemia (CLL) and Waldenström Macroglobulinemia (WM) patients. Although disease-related immune-suppression plays a crucial role in leukemogenesis there is great concern that therapy may further increase the risk of developing these devastating complications.Nucleoside analogs (NA) and alkylating agents are considered appropriate agents in the treatment of both CLL and WM patients. Prolonged immunosuppression related to NA therapy and the incorporation of these agents or their metabolites into DNA, with potentially mutagenic action, leads to speculation that their therapeutic use might be responsible for an increased incidence of second cancer especially when combined with other DNA damaging agents like alkylating agents.In this review the published studies considering the occurrence of secondary MDS and AML in CLL and WM patients are reported and the potential role of chemotherapeutic agents in leukemogenesis is discussed.

Use of white blood cell growth factors and risk of acute myeloid leukemia or myelodysplastic syndrome among elderly patients with non-Hodgkin lymphoma

BACKGROUND

The current study was conducted to evaluate the association between colony-stimulating factor (CSF) use and the risk of developing therapy-related myelodysplastic syndromes or acute myeloid leukemia (t-MDS/AML) among a large cohort of elderly patients with non-Hodgkin lymphoma (NHL) who were treated with chemotherapy.

METHODS

A total of 13,203 NHL patients were identified from the Surveillance, Epidemiology, and End Results-Medicare database who were diagnosed from 1992 through 2002. Patients were followed from their initial chemotherapy date until the date they were diagnosed with t-MDS/AML, death, or last follow-up (October 31, 2006), whichever occurred first.

RESULTS

Overall, 40% (n = 5266) of patients received CSF. During the follow-up period (median follow-up, 2.9 years [range, 1-14.7 years]), 272 (5.2%) patients who were treated with CSF developed t-MDS/AML, compared with 230 (2.9%) patients who did not (P < .0001, log-rank test). The 5-year incidence of t-MDS/AML for patients receiving CSF was 14.1 per 1000 person-years compared with 8.3 per 1000 person-years for patients not receiving CSF. In a multivariable Cox regression analysis adjusted for gender, histology, stage, comorbidities, radiotherapy, and chemotherapy agent, CSF use was found to be independently associated with a 53% increased risk of t-MDS/AML (hazard ratio [HR], 1.53; 95% confidence interval [95% CI], 1.26-1.84). The observed association between CSF use and t-MDS/AML persisted across histologic subgroups (ie, diffuse large B-cell lymphoma, follicular lymphoma, and others). Patients who received both CSF and antimetabolite chemotherapy were found to have a 2.5-fold increased risk of t-MDS/AML (HR, 2.49; 95% CI, 1.91-3.26) compared with patients who received neither agent.

CONCLUSIONS

The current study, which to our knowledge is the first large population-based study published to date, demonstrated that the administration of CSF among elderly NHL patients receiving chemotherapy was associated with an increased risk of t-MDS/AML, although the absolute risk was low.

Molecular basis of CLL

B-cell chronic lymphocytic leukemia (CLL), the most common leukemia in the Western world, results from an expansion of a rare population of CD5+ mature B-lymphocytes. CLL occurs in two forms, aggressive and indolent. For the most part indolent CLL is characterized by low ZAP-70 expression and mutated IgH V(H); aggressive CLL shows high ZAP-70 expression and unmutated IgH V(H). Although clinical features and genomic abnormalities in CLL have been studied extensively, molecular mechanisms underlying disease development are still emerging. In the last few years, several important insights were reported in this area. MiR-15/16 targeting BCL2 and MCL1 and DLEU7 targeting TNF pathway were proposed as tumor suppressors at 13q14, a commonly deleted region in indolent CLL. Molecular details of how activation of TCL1, a critical oncogene in aggressive CLL, results in the initiation of this malignancy were clarified. Importance of these pathways was supported by investigations of several mouse models of CLL. Here, we present what has been learned from these new pathways, discuss mouse CLL models and how these mouse models recapitulate the molecular mechanisms of this common leukemia.

The lysosomotropic agent, hydroxychloroquine, delivered in a biodegradable nanoparticle system, overcomes drug resistance of B-chronic lymphocytic leukemia cells in vitro

Nonviral delivery systems are relatively easy to produce in the large scale, are safe, and elicit a negligible immune response. Nanoparticles (NPs) offer promise as nonviral vectors as biocompatible and -degradable carriers of drugs with targeting to specific sites by surface receptors of monoclonal antibodies (mAbs). We investigated the effect of four PEG-PLGA (polyethylene glycol-polylactic-co-glycolic acid) NP systems on drug-resistant B-chronic lymphocytic leukemia (B-CLL) cells in vitro, three of them encapsulating the drug, hydroxylchloroquine (HDQ), two with NP surface coatings of mAbs (NP1) CD20, (NP2) CD19, and CD20, and one (NP3) with no mAb, but tagged with the fluorescent marker, fluorescein isothiocyanate. The fourth NP system (NP4) was coated with anti-CD19/FITC and anti-CD20/Alexa-Fluor((R)) antibodies, but did not contain the active drug, HCQ. Our data indicate that PEG-PLGA nanoparticles with surface mAbs are suitable for selective drug delivery to B-CLL cells and produce a strong apoptotic effect when loaded with the lysosomotropic agent, HDQ.

Merkel cell carcinoma in a patient with B-cell chronic lymphocytic leukemia treated with cladribine and rituximab

Merkel cell carcinoma (MCC) is an uncommon, neuroendocrine skin tumor with an aggressive clinical course. The etiology of the disease is unknown, although sun exposure and immunosuppression may play a role in its development. Coexistence of MCC with chronic lymphocytic leukemia (CLL) is extremely rare and to our knowledge it has been previously described in only 8 patients. We report a 51-year-old woman who presented with a red lump on the right cheek diagnosed as MCC. She had been diagnosed as having CLL 3 years earlier and was treated with 4 courses of cladribine (2-CdA) and subsequently with 4 courses of 2-CdA combined with rituximab. MCC was diagnosed on the basis of histological and immunohistochemical evaluation 2 months after the last course of 2-CdA and rituximab. Surgical excision with tumor-free margins was performed and local adjuvant radiotherapy was applied. Histopathological and immunohistochemical evaluation of the cervical lymph node specimens showed monotonous and diffuse infiltrate of small CD5+, CD20+, CD23+ lymphocytes and no MCC cells were present. To our knowledge, this is the first reported case of MCC occurring in CLL patients soon after treatment with 2-CdA and/or rituximab. The development of MCC in our patient may suggest that this complication rarely observed in CLL patients may have a link with strongly immunosuppressive therapy with 2-CdA and rituximab.

Skin lesions in chronic lymphocytic leukemia

Cutaneous lesions occur in up to 25% of patients with chronic lymphocytic leukemia (CLL). These can be caused by either cutaneous seeding by leukemic cells (leukemia cutis, LC) and other malignant diseases or nonmalignant disorders. Skin infiltration with B-lymphocyte CLL manifests as solitary, grouped, or generalized papules, plaques, nodules, or large tumors. Prognosis in CLL patients with LC is rather good and many authors claim that it does not significantly affect patients' survival. However, prognosis is poor in patients in whom LC shows blastic transformation (Richter's syndrome) and when leukemic infiltrations in the skin appear after the diagnosis of CLL. Secondary cutaneous malignancies are also frequent complications in patients with CLL. A higher risk was seen in skin cancer, for which eightfold higher occurrence has been stated. There are some suggestions that alkylating agents and purine analogs may be associated with an increased incidence of secondary malignancies in CLL. Nonspecific, secondary cutaneous lesions are frequently observed in CLL patients. The most common secondary cutaneous changes seen in CLL are those of infectious or hemorrhagic origin. Other secondary lesions present as vasculitis, purpura, generalized pruritus, exfoliative erythroderma, and paraneoplastic pemphigus. An exaggerated reaction to an insect bite and insect bite-like reactions have been also observed.

Current status of older and new purine nucleoside analogues in the treatment of lymphoproliferative diseases

For the past few years more and more new cytotoxic agents active in the treatment of hematological malignancies have been synthesized and become available for either in vitro studies or clinical trials. Among them the class of antineoplastic drugs belonging to the purine nucleoside analogues group (PNAs) plays an important role. Three of them: pentostatin (DCF), cladribine (2-CdA) and fludarabine (FA) were approved by Food and Drug Administration (FDA) for the treatment of hematological malignancies. Recently three novel PNAs: clofarabine (CAFdA), nelarabine (ara-G) and forodesine (immucillin H, BCX-1777) have been synthesized and introduced into preclinical studies and clinical trials. These agents seem to be useful mainly for the treatment of human T-cell proliferative disorders and they are currently undergoing clinical trials in lymphoid malignancies. However, there are also several studies suggesting the role of these drugs in B-cell malignancies. This review will summarize current knowledge concerning the mechanism of action, pharmacologic properties, clinical activity and toxicity of PNAs accepted for use in clinical practice, as well as new agents available for clinical trials.

Risk factors for development of a second lymphoid malignancy in patients with chronic lymphocytic leukaemia

Previous studies suggested that patients with chronic lymphocytic leukaemia (CLL) are at a three- to fivefold increased risk of developing a second lymphoproliferative disorder (LPD). This observational cohort study used the Mayo Clinic CLL Database to identify factors associated with developing a second LPD. A second LPD was identified in 26 (2.7%) of 962 CLL patients during a median follow-up of 3.3 years. Diffuse large B-cell lymphoma was the most common subtype of secondary LPD (12 of 26 cases). Patients previously treated for CLL had a trend toward higher prevalence of second LPD (4%) compared with previously untreated patients (2%; P = 0.053). More strikingly, patients treated with purine nucleoside analogues (PNA) had a significantly increased risk of subsequent second LPD (5.2%) compared with patients who had not received PNA (1.9%; P = 0.008). No statistically significant association was observed between risk of second LPD and other CLL characteristics (ZAP-70, CD38, IgV(H) mutation status or cytogenetic abnormalities). In this series, prior treatments with PNA or anthracyclines were the only significant factors associated with risk of developing a second LPD in patients with CLL. Physicians should strictly adhere to established criteria to initiate treatment for CLL patients who are not participating in clinical trials.

Murine models of chronic lymphocytic leukaemia: role of microRNA-16 in the New Zealand Black mouse model

Mouse models are valuable tools in the study of human chronic lymphocytic leukaemia (CLL). The New Zealand Black (NZB) strain is a naturally occurring model of late-onset CLL characterized by B-cell hyperproliferation and autoimmunity early in life, followed by progression to CLL. Other genetically engineered models of CLL that have been developed include (NZB x NZW) F1 mice engineered to express IL5, mice expressing human TCL1A, and mice overexpressing both BCL2 and a tumour necrosis factor receptor-associated factor. The applicability to human CLL varies with each model, suggesting that CLL is a multifactorial disease. Our work with the de novo NZB model has revealed many similarities to the human situation, particularly familial CLL. In NZB, the malignant clones express CD5, zap-70, and have chromosomal instability and germline Ig sequence. We also identified a point mutation in the 3'-flanking sequence of Mirn16-1, which resulted in decreased levels of the microRNA, miR-16 in lymphoid tissue. Exogenous restoration of miR-16 to an NZB malignant B-1 cell line resulted in cell cycle alterations, suggesting that the altered expression of Mirn15a/16-1 is an important molecular lesion in CLL. Future studies utilizing the NZB mouse could ascertain the role of environmental triggers, such as low dose radiation and organic chemicals in the augmentation of a pre-existing propensity to develop CLL.

Pathology of chronic lymphocytic leukemia: an update

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is a clonal lymphoproliferative disorder characterized by proliferation of morphologically and immunophenotypically mature lymphocytes. CLL/SLL may proceed through different phases: an early phase in which tumor cells are predominantly small in size, with a low proliferation rate and prolonged cell survival, and a transformation phase with the frequent occurrence of extramedullary proliferation and an increase in large, immature cells. Although some patients with CLL have an indolent disease course and die after many years of unrelated causes, others have very rapidly disease progression and die of the disease within a few years of the diagnosis. In the past few years, considerable progress has been made in our ability to diagnose and classify CLL accurately. Through cytogenetics and molecular biology, it has been shown that CLL and variants are associated with a unique genotypic profile and that these genetic lesions often have a direct bearing on the pathogenesis and prognosis of the disease. Similarly, the development of antibodies to new biologic markers has allowed the identification of a unique immunophenotypic profile for CLL and variants. Moreover, accumulating evidence suggests that CLL cells respond to selected microenvironmental signals and that this confers a growth advantage and an extended survival to CLL cells. In this article, we will review the progress in the pathobiology of CLL and give an update on prognostic markers and tools in current pathology practice for risk stratification of CLL.

Concomitant presentation of acute myeloid leukemia with T-cell large granular lymphocytic leukemia

T-cell large granular lymphocyte leukemia (T-LGL) also known as T-cell chronic lymphocytic leukemia is rare and comprises a small minority of all small lymphocytic leukemias. The concomitant presentation of T-LGL with acute myeloid leukemia (AML) has not been previously reported. We present an elderly gentleman with concomitant T-LGL and AML (non-M3) diagnosed by a combination of morphologic evaluation, immunophenotyping by flow cytometry, and T-cell gene rearrangement studies. The patient was managed with combination AML chemotherapy. He remains alive and well seven months after initial diagnosis. A brief review of literature is also presented.

Animal models for chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (B-CLL), the most common leukemia in the Western world, results from an expansion of a rare population of CD5+ mature B-lymphocytes. Although clinical features and genomic abnormalities in B-CLL have been studied in considerable detail, the molecular mechanisms underlying disease development has remained unclear until recently. In the last 4 years, several transgenic mouse models for B-CLL were generated. Investigations of these mouse models revealed that deregulation of three pathways, Tcl1-Akt pathway, TNF-NF-kB pathway, and Bcl2-mediated anti-apoptotic pathway, result in the development of B-CLL. While deregulation of TCL1 alone caused a B-CLL phenotype in mice, overexpression of Bcl2 required aberrantly activated TNF-NF-kB pathway signaling to yield the disease phenotype. In this article, we present what has been learned from mice with B-CLL phenotype and how these mouse models of B-CLL were used to test therapeutic treatments for this common leukemia.

Comprehensive Management of the CLL Patient: A Holistic Approach

The current management of B-chronic lymphocytic leukemia (CLL) is no longer straightforward for the practicing hematologist. Rapid advances in diagnostic precision, methods of predicting prognosis, understanding of natural history of CLL, recognition of clinical complications, clarification of the quality of life (QOL) issues facing the CLL patient, and the exciting array of novel treatment approaches have made the care of the CLL patient more demanding. This review is focused on summarizing these advances in order to provide a framework for integrating this knowledge into routine hematologic practice.

Comprehensive management of the CLL patient: a holistic approach

The current management of B-chronic lymphocytic leukemia (CLL) is no longer straightforward for the practicing hematologist. Rapid advances in diagnostic precision, methods of predicting prognosis, understanding of natural history of CLL, recognition of clinical complications, clarification of the quality of life (QOL) issues facing the CLL patient, and the exciting array of novel treatment approaches have made the care of the CLL patient more demanding. This review is focused on summarizing these advances in order to provide a framework for integrating this knowledge into routine hematologic practice.

Progressive immunoglobulin gene mutations in chronic lymphocytic leukemia: evidence for antigen-driven intraclonal diversification

Somatic mutations of immunoglobulin genes characterize mature memory B cells, and intraclonal B-cell diversification is typically associated with expansion of B-cell clones with greater affinity for antigen (antigen drive). Evidence for a role of antigen in progression of intraclonal chronic lymphocytic leukemia (CLL) cell diversification in patients with mutated immunoglobulin genes has not been previously presented. We performed a single-cell analysis of immunoglobulin heavy and light chains in 6 patients with somatically mutated CLL-cell immunoglobulin genes and identified 2 patients with multiple related (oligoclonal) subgroups of CLL cells. We constructed genealogic trees of these oligoclonal CLL-cell subgroups and assessed the effects of immunoglobulin somatic mutations on the ratios of replacement and silent amino acid changes in the framework and antigen-binding regions (CDRs) of the immunoglobulin heavy and light chains from each oligoclonal CLL-cell population. In one subject, the amino acid changes were consistent with an antigen-driven progression of clonally related CLL-cell populations. In the other subject, intraclonal diversification was associated with immunoglobulin amino acid changes that would have likely lessened antigen affinity. Taken together, these studies support the hypothesis that in some CLL cases intraclonal diversification is dependent on antigen interactions with immunoglobulin receptors.

Chronic lymphocytic leukemia: diagnosis and treatment

Traditionally, the goal of therapy in chronic lymphocytic leukemia (CLL) has been palliative, with first-line therapy using alkylating agents and/or involved field radiotherapy (depending on the stage of disease and sites of involvement) because of the older age of affected patients and the low rate of complete remissions (CRs) with no improvement in overall survival despite treatment. With increasing knowledge about the biology, molecular genetics, and prognostic factors of the disease, the philosophy of care for patients with CLL has evolved from palliation to aiming for a potential cure, especially in younger patients. Furthermore, multiple treatment options have emerged, including purine analogues, monoclonal antibodies, and potentially stem cell transplantation. These have been associated with higher frequencies of CRs and longer durations of responses compared to conventional chemotherapy. In addition, a subset of patients treated with chemoimmunotherapy can achieve durable CRs and molecular remissions. This may translate into improved disease-free survival and potentially a "cure." Because of the heterogeneous nature of CLL, new prognostic markers are currently being incorporated into clinical trials to determine their role in routine clinical practice. This review summarizes current therapeutic regimens that are being evaluated in patients with CLL and management of disease-related complications.

Effect of Rapamycin on Mouse Chronic Lymphocytic Leukemia and the Development of Nonhematopoietic Malignancies in Eμ-TCL1 Transgenic Mice

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the world. The TCL1 gene, responsible for prolymphocytic T cell leukemia, is also overexpressed in human B cell malignancies and overexpression of the Tcl1 protein occurs frequently in CLL. Aging transgenic mice that overexpress TCL1 under control of the mu immunoglobulin gene enhancer, develop a CD5+ B cell lymphoproliferative disorder mimicking human CLL and implicating TCL1 in the pathogenesis of CLL. In the current study, we exploited this transgenic mouse to investigate two different CLL-related issues: potential treatment of CLL and characterization of neoplasms that accompany CLL. We successfully transplanted CLL cells into syngeneic mice that led to CLL development in the recipient mice. This approach allowed us to verify the involvement of the Tcl1/Akt/mTOR biochemical pathway in the disease by testing the ability of a specific pharmacologic agent, rapamycin, to slow CLL. We also showed that 36% of these transgenic mice were affected by solid malignancies, in which the expression of the Tcl1 protein was absent. These findings indicate that other oncogenic mechanism(s) may be involved in the development of solid tumors in Emu-TCL1 transgenic mice.

Richter syndrome first manifesting as cutaneous B-cell lymphoma clonally distinct from primary B-cell chronic lymphocytic leukaemia

Richter syndrome (RS) is a transformation to high-grade non-Hodgkin lymphoma in patients with chronic lymphocytic leukaemia (CLL). RS may develop in lymph nodes or rarely extranodally. Skin localization of RS has been described in only a few cases. We present a 77-year-old woman who developed isolated diffuse large B-cell lymphoma (LBCL) in the skin of the nose without any other symptoms of RS. The LBCL in the skin was clonally distinct from the original bone marrow CLL cells. Moreover, LBCL cells were positive for LMP-1 segment of Epstein-Barr virus and overexpressed p53 protein. The patient was successfully treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) and adjuvant local radiotherapy.

Therapy of Chronic Lymphocytic Leukaemia with Purine Nucleoside Analogues

Chronic lymphocytic leukaemia (CLL) is a neoplastic disease of unknown aetiology characterised by an absolute lymphocytosis in peripheral blood and bone marrow. The disease is diagnosed most commonly in the elderly with the median age at diagnosis being about 65 years. The purine nucleoside analogues (PNAs) fludarabine, cladribine (2-chlorodeoxyadenosine) and pentostatin (2'-deoxycoformycin) are highly active in CLL, both in previously treated and in refractory or relapsed patients. These three agents share similar chemical structures and mechanisms of action such as induction of apoptosis. However, they also exhibit significant differences, especially in their interactions with enzymes involved in adenosine and deoxyadenosine metabolism. Recent randomised studies suggest that fludarabine and cladribine have similar activity in CLL. However, clinical observations indicate the existence of cross-resistance between fludarabine and cladribine. Patients who received PNAs as their initial therapy and achieved long-lasting response can be successfully retreated with the same agent. PNAs administered in combination with other chemotherapeutic agents and/or monoclonal antibodies may produce higher response rates, including complete response (CR) or molecular CR, compared with PNAs alone or other treatment regimens. Management decisions are more difficult in elderly patients because of the apparent increase in toxicity of PNAs in this population. In elderly patients, we recommend chlorambucil as the first-line treatment, with PNAs in lower doses in refractory or relapsed patients. Myelosuppression and infections, including opportunistic varieties, are the most frequent adverse effects in patients with CLL treated with PNAs. Therefore, some investigators recommend routine antibacterial and antiviral prophylaxis during and after PNA treatment. This review presents current results and treatment strategies with the use of PNAs in CLL, especially in elderly patients.