Autologous hematopoietic stem cell transplantation as salvage treatment for advanced B cell chronic lymphocytic leukemia

Autologous Stem Cell Transplantation for Chronic Lymphocytic Leukemia - Still a Valid Treatment Option, or is the Game Over?

Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR) has been established as the current standard of care for young and fit patients with chronic lymphocytic leukemia (CLL). In the early nineties of the last century, long before the advent of fludarabine or antibody-based strategies, there was realistic hope that myeloablative therapy followed by autologous stem cell transplantation (autoSCT) might be an effective and potentially curative front-line treatment option for suitable patients with CLL. Since then, several prospective trials have disenthralled this hope: although autoSCT can prolong event and progression-free survival if used as part of early front-line treatment, it does not improve overall survival, while it is associated with an increased risk of late adverse events such as secondary malignancies. In addition, autoSCT lacks the potential to overcome the negative impact of biomarkers that confer resistance to chemotherapy or early relapse. The role of autoSCT has also been explored in the context of FCR, and it was demonstrated that its effect is inferior to the currently established optimal treatment regimen. In view of ongoing attempts to improve on FCR, promising clinical activity of new substances even in relapsed/ refractory CLL patients, exciting novel cell therapy approaches and advantages in the understanding of the disease and detection of Minimal Residual Disease (MRD), autoSCT has lost its place as a standard treatment option for CLL.

Early autologous stem cell transplantation for chronic lymphocytic leukemia: long-term follow-up of the German CLL Study Group CLL3 trial

The CLL3 trial was designed to study intensive treatment including autologous stem cell transplantation (autoSCT) as part of first-line therapy in patients with chronic lymphocytic leukemia (CLL). Here, we present the long-term outcome of the trial with particular focus on the impact of genomic risk factors, and we provide a retrospective comparison with patients from the fludarabine-cyclophosphamide-rituximab (FCR) arm of the German CLL Study Group (GCLLSG) CLL8 trial. After a median observation time of 8.7 years (0.3-12.3 years), median progression-free survival (PFS), time to retreatment, and overall survival (OS) of 169 evaluable patients, including 38 patients who did not proceed to autoSCT, was 5.7, 7.3, and 11.3 years, respectively. PFS and OS were significantly reduced in the presence of 17p- and of an unfavorable immunoglobulin heavy variable chain mutational status, but not of 11q-. Five-year nonrelapse mortality was 6.5%. When 110 CLL3 patients were compared with 126 matched patients from the FCR arm of the CLL8 trial, 4-year time to retreatment (75% vs 77%) and OS (86% vs 90%) was similar despite a significant benefit for autoSCT in terms of PFS. In summary, early treatment intensification including autoSCT can provide very effective disease control in poor-risk CLL, although its clinical benefit in the FCR era remains uncertain. The trial has been registered with www.clinicaltrials.gov as NCT00275015.

Autologous stem cell transplantation as a first-line treatment strategy for chronic lymphocytic leukemia: a multicenter, randomized, controlled trial from the SFGM-TC and GFLLC

Long-term responses have been reported after autologous stem cell transplantation (ASCT) for chronic lymphocytic leukemia (CLL). We conducted a prospective, randomized trial of ASCT in previously untreated CLL patients. We enrolled 241 patients < 66 years of age with Binet stage B or C CLL. They received 3 courses of mini-CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone/prednisolone) and then 3 courses of fludarabine. Patients in complete response (CR) were then randomized to ASCT or observation, whereas the other patients were randomized to dexamethasone, high-dose aracytin, cisplatin (DHAP) salvage followed by either ASCT or 3 courses of fludarabine plus cyclophosphamide (FC). The primary end point was event-free survival (EFS). After up-front treatment, 105 patients entered CR and were randomized between ASCT (n = 52) and observation (n = 53); their respective 3-year EFS rates were 79.8% and 35.5%; the adjusted hazard ratio was 0.3 (95% CI: 0.1-0.7; P = .003). Ninety-four patients who did not enter CR were randomized between ASCT (n = 46) and FC (n = 48); their respective 3-year EFS rates were 48.9% and 44.4%, respectively; the adjusted hazard ratio was 1.7 (95% CI: 0.9-3.2; P = .13). No difference in overall survival was found between the 2 response subgroups. In young CLL patients in CR, ASCT consolidation markedly delayed disease progression. No difference was observed between ASCT and FC in patients requiring DHAP salvage.

Stem cell transplantation in chronic lymphocytic leukaemia - steering a safe course over shifting sands

There is no clear consensus regarding the optimal management of chronic lymphocytic leukaemia. Many patients are diagnosed at an advanced age and will die with chronic lymphocytic leukaemia, but of other unrelated causes. A significant minority are diagnosed at an earlier age, or with more aggressive disease, and despite chemotherapy, are likely to die of chronic lymphocytic leukaemia. The infusion of autologous or allogeneic haemopoietic stem cells, following a variety of conditioning regimes, offers the possibility of longer remissions or even cure. We explore the key questions facing clinicians in this field: Who is it best to transplant? When is it best to transplant? How is it best to transplant?

Transplantation in chronic lymphocytic leukemia: timing and expectations

Stem cell transplantation in chronic lymphocytic leukemia (CLL) is an evolving field. Younger patients with high-risk disease might derive the greatest benefit from this approach and the availability of reduced-intensity conditioning regimens has made allogeneic stem cell transplantation more relevant to patients with CLL. Patient selection, timing of transplantation, and method of conditioning, stem cell delivery and immunosuppression appear to influence outcomes. We collect and review the available data to assist clinical decision-making in this field.

Blood stem cell mobilization and collection in patients with chronic lymphocytic leukaemia: a nationwide analysis

Some reports suggest that blood stem cell mobilization is difficult in a proportion of patients with CLL. We evaluated this issue in a large cohort of CLL patients. One hundred and twenty-eight patients with CLL underwent blood stem cell mobilization during 1995-2005 in Finland. Ninety-five percent of the patients had received fludarabine. The most common mobilization regimen was intermediate-dose CY plus G-CSF (90 patients, 70%). At least 2 x 10(6)/kg CD34+ cells were collected after the first mobilization attempt in 83 patients (65%), whereas 45 patients (35%) failed to reach this collection target. No differences were observed between these patient groups with regard to age, time from the diagnosis to mobilization, number of previous treatment lines, number of fludarabine courses, time from the last fludarabine-containing chemotherapy to mobilization, disease status or degree of marrow infiltration. Patients who failed collection had platelets <100 x 10(9)/l more commonly at the time of mobilization (30 vs 4%, P<0.001). A significant proportion of patients with CLL were difficult to mobilize. Adequate marrow function including platelet counts >100 x 10(9)/l seem to be important factors in terms of successful blood stem cell collection.

Systematic review of high dose chemotherapy and autologous haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: what is the published evidence?

Despite improved responses, chronic lymphocytic leukaemia (CLL) remains incurable with conventional chemotherapy. Patients with poor-risk factors or who fail conventional chemoimmunotherapy are offered autografts, preferably after achieving remission. This report presents the totality of evidence through a systematic review that assessed the efficacy of autografts in CLL. A search of MEDLINE databases from 1966-2006 and hand-search of references identified 82 prospective-randomized, non-randomized comparisons or single-arm trials, of which only nine met our inclusion criteria: two trials were funded by public/government, one by private foundations, one jointly by private/public, and was unclear in five. No randomized controlled trials comparing autografts versus conventional chemotherapy (or chemoimmunotherapy) were found. Six studies were single-arm and three were non-randomized with a control-arm (autologous versus allogeneic). Overall, 361 patients were enrolled, but only 292 were transplanted. Transplant-related mortality ranged from 0% to 9%. Complete responses ranged from 74% to 100% and molecular responses ranged from 57% to 88%. Overall survival ranged from 68% at 3 years to 58% at 6 years. It is uncertain whether autograft is superior to conventional therapy. The high incidence of myelodysplastic syndrome (9-12%) is particularly concerning in CLL, where median survival is 9 years.

Stem-cell transplantation in chronic lympocytic leukaemia

Excellent response rates are now achieved with modern chemoimmunotherapeutic approaches in chronic lymphocytic leukaemia (CLL), but the disease remains incurable. Younger patients and those with adverse prognostic factors will die from their disease, and are therefore candidates for clinical trials investigating the potential role of haematopoietic stem-cell transplantation (SCT) in the management of their disease. Autologous SCT is feasible and safe, but there is a high incidence of subsequent relapse. Myeloablative allogeneic SCT is associated with high treatment-related morbidity and mortality but few late relapses. Attempts to exploit the graft-versus-leukaemia effect of allogeneic donor cells but to reduce the toxicity are being explored in studies of reduced-intensity conditioning allogeneic SCT in CLL. With many potential treatments available, appropriate patient selection and the timing of SCT in the management of CLL remain controversial and the focus of ongoing clinical trials.

Chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world and is due to the accumulation of mature B lymphocytes in the peripheral blood, bone marrow and secondary lymphoid organs. The leukemic cells show a distinct phenotype, which is essential to reach the correct diagnosis. Despite the phenotypic homogeneity, the clinical outcome may be significantly different. Some patients have an indolent leukemia, with long survival while others experience an aggressive disease, with early and frequent need of treatment. At present, no chemotherapeutic regimens can be considered curative and all patients will die with (or because of) their disease. In recent years, research on CLL has led to important discoveries that help defining patients' prognosis at the moment of diagnosis. These prognostic factors, which are derived from the biological features of the leukemic lymphocytes, are now rapidly moved into the clinical arena. They are used to stratify patients in selected clinical trials to assess the value of early and more modern treatments, which are becoming available to hematologists.

Hematopoietic Cell Transplantation for Chronic Lymphocytic Leukemia: An Evolving Concept

Recent years have brought major strides to our understanding of prognostic pathobiologic factors in patients with chronic lymphocytic leukemia. This has allowed identification of high-risk patients who may benefit from more aggressive therapies, including hematopoietic cell transplantation. High-dose chemotherapy followed by autologous hematopoietic cell transplantation is feasible, and results in encouraging responses, including molecular responses, with low transplant-associated mortality. However, it has failed to show a plateau effect on survival curves. On the other hand, there is convincing evidence that immunologically mediated graft-versus-leukemia effect of donor T cells are responsible for lowering the incidence of relapse and allowing possible "cure" in allograft recipients, albeit at the expense of high treatment-associated mortality using conventional myeloablation. Reducing the intensity of conditioning regimens has translated into lesser toxicity with reasonable preservation of its curative potential. Autologous or allogeneic hematopoietic cell transplantation in high-risk chronic lymphocytic leukemia remain promising and evolving treatment options. Treatment of CLL should consider stratification according to modern prognostic markers.

Revisiting the role of hematopoietic stem cell transplantation in chronic lymphocytic leukemia

Since the advent of hematopoietic stem cell transplantation more than 40 years ago, numerous methods of transplantation have been developed, modified and improved upon. Although hematopoietic stem cell transplantation has been used in a variety of malignant diseases since then, its use in the treatment of chronic lymphocytic leukemia has recently started to gain interest. Patients with chronic lymphocytic leukemia are generally elderly, and because of its relatively benign course, they were not considered suitable candidates for hematopoietic stem cell transplantation. Nonetheless, there have been marked improvements in transplantation techniques, including better conditioning regimens that have decreased treatment-related morbidity and mortality. In this article, the authors review the most recent data on hematopoietic stem cell transplantation in chronic lymphocytic leukemia as well as the change in risk stratification based on newer prognostic factors and its impact on treatment decisions in chronic lymphocytic leukemia.

Stem cell transplantation for chronic lymphocytic leukaemia

Early results of autologous stem cell transplantation (ASCT) in chronic lymphocytic leukaemia (CLL) suggested a significant proportion of patients remained disease-free for years, raising the possibility of cure. More recent studies have shown no evidence of a plateau in the survival curves indicating that, at best, ASCT may only prolong disease-free survival. Problems remain over progenitor cell mobilization and one study has raised anxieties about post-transplant myelodysplasia. The impact of ASCT in CLL will only be properly ascertained in a randomized clinical trial and this in underway in Europe. Initial results of conventional allogeneic transplantation (allo-SCT) were very disappointing, with an unacceptably high mortality, but did show that cure was possible in some patients. The introduction of reduced intensity conditioning has limited the early transplant-related mortality but it remains too early to determine what proportion of patients will be cured. In view of these uncertainties, is important that reduced intensity allo-SCT for CLL is conducted in the context of a clinical trial. Finally, CLL is very heterogeneous condition and great deal more is becoming understood about the prognostic factors. These will become important in allowing patients and their physicians a choice in balancing the risks of various treatment options.

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.

Role of auto- and allotransplantation in B-cell chronic lymphocytic leukemia

Although important progress has been made in its management, B-cell chronic lymphocytic leukemia (CLL) remains incurable with standard therapies. Hematopoietic stem-cell transplants (HSCT) are frequently being offered to individuals with CLL, the hope being that, as in other hematologic malignancies, they can prolong survival in or even cure some patients. This article analyzes which patients with CLL are appropriate candidates for HSCT, current transplant procedures, results with autologous and allogeneic HSCT, and future trends in transplantation in this form of leukemia.

The role of stem cell transplantation in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) generally follows an indolent clinical course and usually occurs in the elderly. However, the disease is heterogeneous with some patients having a more aggressive clinical course and short survival. Although the role of fludarabine in combination with other chemotherapy drugs and/or monoclonal antibody therapy appears promising, to date chemotherapy has not been curative in this disease. At present, the only potential cure for CLL appears to be stem cell transplantation (SCT), but its role in the management of CLL has not been established. In particular, patient selection for consideration of SCT, timing of SCT in the clinical course of CLL, selection of autologous versus allogeneic SCT, use of nonmyeloablative regimens, and exploitation of the graft-versus-leukemia (GVL) effect are currently under investigation.

Results of the MRC pilot study show autografting for younger patients with chronic lymphocytic leukemia is safe and achieves a high percentage of molecular responses

We have assessed autologous stem cell transplantation after treatment with fludarabine in previously untreated patients with chronic lymphocytic leukemia (CLL). This study is the first to enroll previously untreated patients and follow them prospectively. The initial response rate to fludarabine was 82% (94 of 115 patients). Stem cell mobilization was attempted in 88 patients and was successful in 59 (67%). Overall 65 of 115 patients (56%) entered into the study proceeded to autologous transplantation. The early transplant-related mortality rate was 1.5% (1 of 65 patients). The number of patients in complete remission after transplantation increased from 37% (24 of 65) to 74% (48 of 65), and 26 of 41 patients (63%) who were not in complete remission at the time of their transplantation achieved a complete remission after transplantation. The 5-year overall and disease-free survival rates from transplantation were 77.5% (CI, 57.2%-97.8%) and 51.5% (CI, 33.2%-69.8%), respectively. None of the variables examined at study entry were found to be predictors of either overall or disease-free survival. Sixteen of 20 evaluable patients achieved a molecular remission on a polymerase chain reaction (PCR) for immunoglobulin heavy-chain gene rearrangements in the first 6 months following transplantation. Detectable molecular disease by PCR was highly predictive of disease recurrence. It is of concern that 5 of 65 (8%) patients developed posttransplant acute myeloid leukemia/myelodysplastic syndrome.

The prognostic impact of autologous stem cell transplantation in patients with chronic lymphocytic leukemia: a risk-matched analysis based on the VH gene mutational status

To assess the therapeutic value of sequential high-dose therapy (SHDT) including autologous stem cell transplantation in chronic lymphocytic leukemia (CLL) we performed a risk-matched comparison between 66 patients who had undergone a uniform SHDT regimen and a database of 291 patients treated conventionally. Matching variables were age, Binet stage, IgVH (variable region of the immunoglobulin heavy chain) gene mutational status, and lymphocyte count. Forty-four pairs fully matched for all 4 variables were identified. Patient groups were well balanced for additional risk factors including adverse genomic abnormalities and CD38 expression. With an overall median follow-up time of 70 and 86 months, respectively, survival was significantly longer for the SHDT patients than for the conventionally treated patients when calculated from diagnosis (hazard ratio [HR] 0.39; P=.03 [log rank]) or from study entry (HR 0.32; P=.006). The benefit for the SHDT group remained significant when the analyses were restricted to those 58 patients who had an unmutated VH status. Cox regression analysis confirmed SHDT as independent favorable prognostic factor for survival from diagnosis (HR 0.38, P=.04) as well as from study entry (HR 0.38, P=.03). These data suggest a survival benefit for patients with poor-risk CLL receiving SHDT during the course of their disease.

Induction of chronic lymphocytic leukemia (CLL)-specific CD4- and CD8-mediated T-cell responses using RNA-transfected dendritic cells

Recently, it was demonstrated that transfection of dendritic cells (DCs) with tumor-derived RNA can elicit effective T-cell responses. This technique does not require the definition of the tumor antigen or HLA haplotype of the patients. We applied this approach to induce HLA class I- and class II-restricted T-cell responses directed against malignant cells from patients with chronic lymphocytic leukemia (B-CLL). Here, we show that DCs generated from monocytes of patients with B-CLL induce leukemia-specific cytotoxic and proliferative T-cell responses on transfection with total RNA isolated from autologous leukemic B lymphocytes. Standard 51Cr-release assays showed specific major histocompatibility complex (MHC) class I-restricted cytotoxic activity against the autologous leukemic B cells and DCs transfected with CLL-RNA, whereas nonmalignant B cells were spared. The specificity of the cytotoxic T-lymphocyte (CTL) response was confirmed using cold target inhibition assays and by blocking HLA class I molecules. Furthermore, we established a protocol for the amplification of whole B-CLL mRNA. The use of DCs transfected with in vitro amplified B-CLL mRNA elicited specific T-cell responses similar to the results obtained with native mRNA. These data suggest that vaccinations using DCs transfected with RNA might be a potent new strategy in the treatment of CLL.

Role of autologous stem cell transplantation in chronic lymphocytic leukemia

Autologous hematopoietic stem sell transplantation is increasingly considered for treatment of patients with high-risk chronic lymphocytic leukemia. Patients not eligible for allogeneic hematopoietic stem cell transplantation with poor prognosis disease, documented chemosensitivity, and a minimal tumor burden at the time of hematopoietic stem cell transplantation can be treated with autologous hematopoietic stem cell transplantation currently using peripheral blood stem cells. Different purging methods to obtain sources of stem cells free of tumor contamination are currently being evaluated. Major concerns are judicious selection of which patients may benefit from this approach, the subsequent risk of relapse of disease, and the long-term risk of development of secondary malignancies, including myelodysplastic syndrome and acute myelogenous leukemia. Recognizing and reducing the risk factors that contribute to relapse and complications of the procedure should improve outcome after autologous hematopoietic stem cell transplantation. With the increasing use, increasing effectiveness, and low treatment-related mortality associated with nonmyeloablative conditioning regimens, the question of whether a patient should be offered autologous or allogeneic hematopoietic stem sell transplantation can be a difficult one. Defining salvage settings for relapse and implementing a tandem autologous/allogeneic hematopoietic stem cell transplantation approach may provide a method to improve outcome for selected patients.

Unmutated immunoglobulin variable heavy-chain gene status remains an adverse prognostic factor after autologous stem cell transplantation for chronic lymphocytic leukemia

An unmutated germ line configuration of the immunoglobulin variable heavy-chain gene (VH) has emerged to be a crucial adverse prognostic factor in chronic lymphocytic leukemia (CLL) under conventional treatment. The purpose of the present study was to investigate whether the VH mutational status retains its prognostic value in CLL also in the setting of autologous stem cell transplantation (SCT). Therefore, we investigated the mutational status in 58 patients with CLL who underwent myeloablative radiochemotherapy with SCT. Rearranged VH genes were analyzed by multiplex polymerase chain reaction (PCR) and direct sequencing using FR1 family-specific primers and JH consensus primers. Twenty patients (34%) showed less than 98% homology compared with germ line VH sequences and were considered as mutated, whereas 38 patients (66%) had an unmutated VH status (median mutational rate of 0%; range, 0%-1.7%). An unmutated VH configuration was strongly correlated with the presence of short lymphocyte doubling time (P =.003) and high lymphocyte count (P =.005). Time to clinical relapse and time to recurrence of monoclonal B cells as assessed by consensus IgH CDR3 PCR was significantly shorter in the group with unmutated VH genes (2-year probability 19% versus 0%, P =.0008, and 34% versus 9%, P =.0006, respectively). These results show that in CLL, an unmutated VH gene status of the tumor clone remains an adverse prognostic factor after SCT. Nevertheless, the hitherto only 3 deaths and the median treatment-free interval of 49 months in the unmutated cohort suggest a beneficial effect of SCT for this high-risk population in comparison to conventional treatment.

Novel flow-cytometric analysis based on BCD5+ subpopulations for the evaluation of minimal residual disease in chronic lymphocytic leukaemia

We describe a new flow-cytometric analysis using quadruple labelling with anti-CD19, CD20, CD5, CD79b monoclonal antibodies and sequential gating. We determined a novel criteria defined by BCD5+CD79b-/low/total BCD5+ cells ratio (BCD5+R), and compared it with the previous definition of phenotypic remission, based on CD19+CD5+ coexpression, and with complementarity-determining region 3 polymerase chain reaction (CDR3 PCR) and clonotypic PCR (cPCR). A series of 54 peripheral blood samples from 21 chronic lymphocytic leukaemia (CLL) patients in complete haematological remission and a series of 16 from normal volunteers were analysed. In normal controls, the BCD5+R was always < 0.2. The sensitivity of the BCD5+R was 1 x 10-4vs 5 x 10-2 for CDR3 PCR and 1 x 10-5 for cPCR. Among the 54 CLL samples, 35 had a BCD5+R < 0.2 and showed polyclonal CDR3 PCR, whereas the cPCR was positive in 12 out of 20 tested. In the remaining 19 samples, BCD5+R was > 0.2, CDR3 PCR was monoclonal in 16 out of 19 and cPCR positive in 14 out 14 tested, including one out of three samples with polyclonal CDR3 amplification. Even though cPCR remains the most sensitive method to evaluate MRD, this new, sensitive and specific flow cytometric parameter, the BCD5+R, is more suitable than CDR3 PCR for routine clinical MRD assessment in CLL.

B-chronic lymphocytic leukemia: practical aspects

B-CLL is the most common adult leukemia in the Western world. It is a neoplasia of mature looking B-monoclonal lymphocytes co-expressing the CD5 antigen (involving the blood, the bone marrow, the lymph nodes and related organs). Much new information about the nature of the neoplastic cells, including chromosomal and molecular changes as well as mechanisms participating in the survival of the leukemic clone have been published recently, in an attempt to elucidate the biology of the disease and identify prognostic subgroups. For the time being, clinical stage based on Rai and Binet staging systems remains the strongest predictor of prognosis and patients' survival, and therefore it affects treatment decisions. In the early stages treatment may be delayed until progression. When treatment is necessary according to well-established criteria, there are nowadays many different options. Chlorambucil has been the standard regimen for many years. During the last decade novel modalities have been tried with the emphasis on fludarabine and 2-chlorodeoxyadenosine and their combinations with other drugs. Such an approach offers greater probability of a durable complete remission but no effect on overall survival has been clearly proven so far. Other modalities, included in the therapeutic armamentarium, are monoclonal antibodies, stem cell transplantation (autologous or allogeneic) and new experimental drugs. Supportive care is an important part of patient management and it involves restoring hypogammaglobulinemia and disease-related anemia by polyvalent immunoglobulin administration and erythropoietin respectively.

Alkylating agents and nucleoside analogues in the treatment of B cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in the Western world. The natural clinical course is highly variable and chemotherapy is usually not indicated in early and stable disease. Treatment is needed in the progressive form of this leukemia. Chlorambucil, with or without steroids, has been for many years the drug of choice in the treatment of CLL. More recently, treatment approaches have included nucleoside analogues, (NA) fludarabine (FAMP) and cladribine (2-CdA, 2-chlorodeoxyadenosine), which seem to be the treatment of choice for patients failing standard therapies. Their role as first line therapy is being investigated in randomized trials and the results have recently been published. These studies have shown a higher overall response and complete remission (CR) rate and longer response duration in patients treated initially with NA than with chlorambucil or cyclophosphamide-based combination regimens. In contrast, overall survival is similar in patients treated with NA and alkylating agents. However, the randomized trials were designed as crossover studies which may influence survival. Combined use of NA with other cytotoxic drugs, cytokines, monoclonal antibodies and other agents may increase the CR and prolong survival time. However, the results of randomized trials comparing combination treatment with NA alone are not yet available. In conclusion, alkylating agents still have an important place in the routine management of the majority of CLL patients. NA should be routinely used as second line treatment and possibly as first line therapy in younger patients, who are candidates for potentially curative treatment such as stem cell transplantation and/or monoclonal antibodies.

Allogeneic and autologous transplantation for chronic lymphocytic leukemia

Autologous and allogeneic transplantation are increasingly used in the management of patients with chronic lymphocytic leukemia. Many questions regarding patient selection, efficacy and outcome are unresolved, hence a review of the literature through Medline search. Autologous transplantation for CLL has been used mainly in selected patients under the age of 60. Conditioning typically involves total body irradiation (TBI). Bone marrow and more recently peripheral blood stem cells are used. Treatment-related mortality in most series is less than 10%. Molecular remissions after autologous transplantation are common, and clinical remissions can be prolonged in some patients. Randomized studies are needed to establish whether autologous transplantation confers a survival benefit over standard chemotherapy approaches. Allogeneic transplantation has a considerable treatment-related mortality, but durable remissions sometimes occur in patients with advanced disease. The use of non-myeloablative 'mini-transplants' has been investigated as a method to reduce treatment-related mortality, but prolonged follow-up will be required to establish the cure rate obtained with this procedure. Autologous and allogeneic transplantation are promising treatment modalities. Further refinements of transplant techniques and properly designed prospective studies are necessary to establish the role of stem cell transplantation in the overall management of CLL.

Management of chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common form of adult leukaemia in Western countries. The diagnosis requires mature-appearing lymphocytes in the peripheral blood to >5 x 10(9)/L. The immunophenotype typically includes B cell antigens CD19, CD20 and CD23, low expression of surface immunoglobulin and CD5+, with other T cell antigens absent. Bone marrow biopsy, although not required for diagnosis, must show at least 30% lymphocytes. Cytogenetic abnormalities are frequent in patients with CLL, and may be associated with poor prognosis. Clinically, most patients are asymptomatic at presentation, with incidental lymphadenopathy and/or hepatosplenomegaly in the routine physical examination. Infections by opportunistic pathogens are the major cause of death. Aggressive transformation occurs in 10% of patients with CLL, most commonly prolymphocytic leukaemia (PLL) and Richter's syndrome. PLL de novo must be differentiated from PLL of an aggressive transformation. The incidences of autoimmune diseases and solid or haemopoietic secondary malignancies are increased in patients with CLL. Clinical stage is the strongest prognostic factor in CLL. There is no indication for early intervention. The current recommendation to start treatment includes disease-related symptoms, massive and/or progressive hepatosplenomegaly or lymphadenopathy, increasing bone marrow failure, autoimmune disease, and recurrent infections. Alkylating agents (e.g. chlorambucil) and nucleoside analogues (e.g. fludarabine) are the most active agents for CLL. Fludarabine induces higher response rates, but no improvement in overall survival has been observed. Fludarabine is the drug of choice for the majority of patients with CLL. Chlorambucil may be helpful for elderly patients with poor performance, and for patients who do not tolerate fludarabine. No drug combination is better than single agents. For patients refractory to initial treatment, referral to a clinical trial is the best choice. Other salvage therapy includes retreatment with the same initial agent (chlorambucil or fludarabine) if initial response was observed, or fludarabine for patients refractory to chlorambucil. Promising new approaches include cycle-active agents, nelarabine, biological therapy such as anti-CD52 monoclonal antibody, bone marrow transplantation, including the use of submyeloablative preparative regimens ('minitransplant') to induce graft-versus-leukaemia effect, and gene therapy. Prophylactic antibacterials and intravenous immunoglobulin should not be used routinely during supportive care. Epoetin may be helpful for patients who have anaemia without obvious cause. Assessment of response to therapy in CLL has been updated by the National Cancer Institute Working Group, and these guidelines are used worldwide for clinical trials.

Stem cell transplantation for indolent lymphoma

Stem cell transplantation (SCT) has become the treatment of choice for patients with relapsed aggressive non-Hodgkin's lymphoma (NHL). The role of SCT in the management of patients with low-grade NHL remains more controversial, although increasing numbers of patients with advanced-stage follicular lymphoma, mantle cell lymphoma, and chronic lymphocytic leukemia are now undergoing SCT. To date, most patients with NHL have been treated with autologous SCT, currently using peripheral blood stem cells (PBSC) mobilized by chemotherapy and recombinant growth factors. There is increasing concern regarding toxicity of autologous SCT, especially the higher than expected long-term risk of development of myelodysplastic syndrome. This, among other factors, has led to renewed interest in the role of allogeneic SCT for patients with NHL. A major advantage of allogeneic SCT is the potential to exploit a graft-versus-lymphoma effect, and many studies are underway exploring the possibility of manipulating donor cells to maximize T cell responsiveness against lymphoma.

Chronic lymphocytic leukemia

Significant strides have been made in our understanding of the biology and treatment of B cell chronic lymphocytic leukemia. Recent studies have defined cytogenetic and molecular lesions that may be responsible for leukemogenesis or disease progression. Molecular analyses of immunoglobulin genes have delineated two or more subgroups of chronic lymphocytic leukemia that may differ in their clinical behavior. Research in the biochemistry of chronic lymphocytic leukemia has provided insight into the noted resistance of leukemia cells to cytotoxic drugs. Investigations into the immunology has revealed mechanisms whereby chronic lymphocytic leukemia cells can contribute to the immune deficiency that commonly develops in patients with this disease. Clinical studies have delineated factors that are helpful in predicting prognosis and have provided data on promising new therapies for patients with this disease, including stem cell transplantation, monoclonal antibodies, and gene therapy.