Leukemia

The US Food and Drug Administration recently approved rituximab (Rituxan) to treat certain patients with chronic lymphocytic leukemia (CLL).

Unlike conventional radiation, Yttrium-90-ibritumomab tiuxetan (Zevalin) induces cellular damage only in the targeted tumor cells and has demonstrated activity in follicular and diffuse large B-cell non-Hodgkin’s lymphoma.

Multiple myeloma remains the second most common hematologic malignancy in the United States, after non-Hodgkin lymphoma.

Chronic lymphocytic leukemia (CLL) is a clonal malignancy that results from expansion of the mature lymphocyte compartment. This expansion is a consequence of prolonged cell survival, despite a varied cell. The affected lymphocytes are of B-cell lineage in 95% of cases, and the remaining cases involve T lymphocytes, representing a distinct disorder.

Hematopoietic malignancies account for 6% to 8% of new cancers diagnosed annually. In the year 2009, an estimated 44,790 new cases of leukemia were diagnosed, and 21,870 deaths were attributable to leukemias of all types. The total age-adjusted incidence of leukemia, including both acute and chronic forms, is 9.6 per 100,000 population; the incidence of acute lymphoblastic leukemia (ALL) is 1.5 per 100,000 and of acute myelogenous leukemia (AML) is 2.7 per 100,000 population.

The incidence rates of non-Hodgkin lymphoma (NHL) in the United States have almost doubled between 1970 and 1990, representing one of the largest increases of any cancer. Although the overall incidence rates of NHL began to stabilize in the late 1990s, the temporal trends varied by histologic subtype. Some of this increase may be artifactual, resulting from improved diagnostic techniques and access to medical care, or directly related to the development of NHL in 25- to 54-year-old men with human immunodeficiency virus (HIV) infection. However, additional factors must be responsible for this unexpected increase in frequency of NHL that has been observed throughout the United States.

In 2009 approximately 8,510 new cases of Hodgkin lymphoma (HL) will be diagnosed in the United States. Over the past 4 decades, advances in radiation therapy and the advent of combination chemotherapy have tripled the cure rate of patients with HL. In 2009, more than 80% of all newly diagnosed patients can expect a normal, disease-free life span.

Induction therapy with higher daily doses of daunorubicin improved complete response and boosted overall survival in younger patients with acute myelogenous leukemia, according to results of the phase III ECOG E1900 trial.

No branch of oncology has been more attuned to the vision of new genetically engineered targeted therapies than the field of hematopoietic malignancies. Ujjani and Cheson have produced a masterful summary of one extremely important component of the targeted therapy revolution-the realm of monoclonal antibodies directed against malignant lymphoma surface antigens.[1] The review presents a wonderful update and a glimpse of future potentially curative macromolecular cocktails. It is an attractive vision.

he treatment of B-cell malignancies has been revolutionized by the availability of safe and effective monoclonal antibodies. The addition of rituximab to standard chemotherapy regimens prolongs the survival of patients with diffuse large B-cell lymphoma (DLBCL) and follicular non-Hodgkin lymphoma. Nevertheless, indolent and mantle cell lymphomas remain incurable, and 30% to 40% of patients with DLBCL still die from their disease. Much ongoing research has focused on optimizing monoclonal antibody use, integrating them into multiagent regimens, and developing newer antibodies. Attempts to improve on the efficacy of monoclonal antibody–based therapy have included altering the dosing schedule, optimizing patient selection, maintenance therapy, improving upon the rituximab molecule, radioimmunotherapy, as well as combinations with cytotoxic molecules and other novel agents. Preliminary data with a number of treatment regimens are promising in indolent and aggressive lymphomas. The eventual goal of targeted therapies is to individualize treatment to increase response and survival, while reducing treatment-related toxicity.

In this review, Ujjani and Cheson present a useful overview of the array of existing and developing roles for monoclonal antibodies in the management of B-cell non-Hodgkin lymphomas (NHLs). These roles may be characterized as single-agent antibody therapy, use in combination with chemotherapy and/or other antibodies, and use following an initial regimen (consolidation/maintenance). Rituximab (Rituxan), the first monoclonal antibody approved for B-cell NHL, clearly has had greatest application in each of these arenas, but it has now been joined by alemtuzumab (Campath) and ofatumumab (Arzerra) as approved single-agent therapies. Also highlighted are a number of other antibodies aimed at B-cell targets: veltuzumab, GA101, AME-133 (CD20), epratuzumab (CD22), lumiliximab (CD23), galiximab (CD80), dacetuzumab (CD40), mapatumumab, lexatumumab (TRAIL), and approaches to improve antibody therapy such as conjugation with radioisotopes or toxins.

Peripheral T-cell lymphomas, or PTCLs, represent an uncommon and biologically heterogeneous group of hematologic malignancies, accounting for less than 10% of all non-Hodgkin lymphomas worldwide, with marked geographic differences. Due to their low prevalence, variable clinical presentation and phenotypic heterogeneity, these lymphomas have historically been difficult to diagnose and categorize. Since the introduction of immunophenotyping and molecular genetic methods, as well as the development of comprehensive classification systems, there have been significant advances in diagnostic accuracy, classification, and our understanding of the biologic behavior of different PTCL subtypes. However, the molecular pathogenesis of most subtypes of PTCL remains incompletely understood, and treatment outcomes with conventional anthracycline-based chemotherapy regimens are generally significantly inferior to those in aggressive B-cell lymphomas.

Peripheral T-cell lymphomas (PTCLs) are uncommonly encountered malignancies in the United States, and hepatosplenic T-cell lymphoma (HSTCL), subcutaneous panniculitis-like T-cell lymphoma (SPTCL), and enteropathy-type T-cell lymphoma (ETTCL) are rare subtypes of PTCLs that often present with primarily extranodal disease. Despite the fact that these tumors have distinct clinical and pathologic features, they are often diagnosed after significant delay. The combination of delay in diagnosis with ineffective therapies has resulted in a poor prognosis in most cases. Techniques that identify T-cell receptor gene rearrangements and flow cytometry that can identify characteristic immunophenotypes have guided our understanding of the underlying cell of origin of these rare PTCLs. As knowledge regarding the biology of these lymphomas increases alongside the development of newer therapeutics with novel mechanisms, clinicians must accordingly improve their familiarity with the clinical settings in which these rare malignancies arise as well as the pathologic features that make them unique

NEW ORLEANS-Genentech and Biogen announced at ASH 2009 that the three-year follow-up of the CLL8 trial demonstrated that rituximab (Rituxan) plus fludarabine and cyclophosphamide (FC) chemotherapy improved overall survival in patients with previously untreated chronic lymphocytic leukemia (CLL) vs FC therapy alone.

In this issue of ONCOLOGY, Dr. Tobinai presents a thorough and thoughtful review of the current state of the art of HTLV-related adult T-cell leukemia/lymphoma (ATLL). As described, ATLL is most prevalent in Asia, where it has also been most studied, but is also seen in patients from other HTLV-endemic areas including the Caribbean, South America, and parts of Africa. ATLL is rare in North America and Europe, representing 1% to 2% of T-cell lymphomas compared to 25% in Asia.[1]

In this issue of ONCOLOGY, Tobinai reviews the management of human T-cell lymphotropic virus type 1 (HTLV-1)–associated adult T-cell leukemia/lymphoma (ATL). Although rare in the United States, an estimated 10 to 20 million people are infected with HTLV-1 worldwide and 2% to 5% will develop ATL.[1]

Sunesis Pharmaceuticals, Inc, announced that the US Food and Drug Administration has granted voreloxin orphan drug designation for the treatment of acute myeloid leukemia (AML). Sunesis is currently conducting two phase II clinical trials of voreloxin in AML: a single-agent study (REVEAL-1) in newly diagnosed elderly AML patients unlikely to benefit from standard induction chemotherapy and a study evaluating the drug in combination with cytarabine in relapsed/refractory AML.

Adult T-cell leukemia/lymphoma (ATL) is defined as a histologically or cytologically proven peripheral T-cell malignancy associated with a retrovirus, human T-cell lymphotropic virus type I (HTLV-1).[1] Southwestern Japan is the district with the highest prevalence of HTLV-1 infection and the highest incidence of ATL in the world. A high prevalence of HTLV-1 infection is also found in the Caribbean islands, tropical Africa, South America, and northern Oceania.

The purpose of this review is to familiarize oncologists with the clinical and pathologic features of this relatively rare disease spectrum. This should enable appropriate clinical management and reassurance of patients concerned about their prognosis.

Our ability to treat patients with B-cell lymphomas has improved dramatically over the past few decades. Today the majority of patients with diffuse large B-cell lymphoma are cured, the survival of patients with low-grade follicular lymphoma is improving (ie, some estimates have the average survival more than doubling), most patients with Hodgkin lymphoma (also a B-cell lymphoma) are cured, most patients with Burkitt lymphoma are cured, and our ability to diagnose and treat patients with the various marginal zone lymphomas has improved considerably.

Allos Therapeutics has received accelerated FDA approval for Folotyn (pralatrexate) as a single-agent treatment in patients with relapsed or refractory peripheral T-cell lymphoma.

One of the greatest challenges facing the physician caring for patients with chronic lymphocytic leukemia (CLL) is the heterogeneity of this disease. Over the past decade, there have been major advances in understanding the pathophysiology of CLL, and in the identification of biomarkers that are helpful to predict the clinical course for individual patients. Over the same period, the available therapeutic options have developed dramatically, exemplified by the introduction of combination therapy with purine analogs and monoclonal antibodies, resulting in significant opportunities to induce complete remission (CR) in CLL patients.

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease with an extremely variable course. Survival after diagnosis can range from months to decades. As the pathogenesis of the disease is increasingly understood, we begin to unfold the molecular patterns that define the different prognostic subgroups and to develop strategies to predict the clinical course.

Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia in the Western hemisphere. Both the Rai and Binet staging systems have been important clinical tools for predicting outcomes of this heterogeneous disease.

Lymphoblastic lymphoma (LBL) is a rare disease, comprising about 2% of all non-Hodgkin lymphomas (NHLs) in adults.[1] It is a highly aggressive subtype of lymphoma, most commonly of precursor T-cell origin, occurring most frequently in adolescents and young adults, with male predominance and frequent mediastinal, bone marrow, and central nervous system (CNS) involvement.