Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)

Treatment of chronic lymphocytic leukemia (CLL) ranges from periodic observation with treatment of infectious, hemorrhagic, or immunologic complications to a variety of therapeutic options, including steroids, alkylating agents, purine analogs, combination chemotherapy, monoclonal antibodies, and transplant options.[1] Because this disease is generally not curable, occurs in an elderly population, and often progresses slowly, it is most often treated in a conservative fashion.[2] In asymptomatic patients, treatment may be deferred until the patient becomes symptomatic as the disease progresses. Since the rate of progression may vary from patient to patient, with long periods of stability and sometimes spontaneous regressions, frequent and careful observation is required to monitor the clinical course. A meta-analysis of randomized trials showed no survival benefit for immediate versus delayed therapy for patients with early stage disease, nor for the use of combination regimens incorporating an anthracycline compared with a single-agent alkylator for advanced stage disease.[3][Level of evidence: 1iiA] A variety of clinical factors, including beta-2-microglobulin, lymphocyte doubling time, and cytogenetic abnormalities, may be helpful in predicting progression of disease.[4]

Infectious complications in advanced disease are in part a consequence of the hypogammaglobulinemia and the inability to mount a humoral defense against bacterial or viral agents. Herpes zoster represents a frequent viral infection in these patients, but infections with Pneumocystis carinii and Candida albicans may also occur. The early recognition of infections and the institution of appropriate therapy are critical to the long-term survival of these patients. A randomized study of intravenous immunoglobulin (400 mg/kg every 3 weeks for 1 year) in patients with CLL and hypogammaglobulinemia produced significantly fewer bacterial infections and a significant delay in onset of first infection during the study period.[5] There was, however, no effect on survival. Routine chronic administration of intravenous immunoglobulin is expensive, and the long-term benefit (>1 year) is unproven.[6,7]

Second malignancies and treatment-induced acute leukemias may also occur in a small percentage of patients. Transformation of CLL to diffuse large cell lymphoma (Richter syndrome) carries a poor prognosis with a median survival of less than 1 year, though 20% of the patients may live more than 5 years after aggressive combination chemotherapy.[8] (Refer to the PDQ summary on Adult Non-Hodgkin Lymphoma Treatment for more information.)

Autoimmune hemolytic anemia and/or thrombocytopenia can occur in patients with any stage of CLL.[9] Initial therapy involves corticosteroids with or without alkylating agents (fludarabine can worsen the hemolytic anemia). It is frequently advisable to control the autoimmune destruction with corticosteroids, if possible, prior to administering marrow-suppressive chemotherapy because such patients may be difficult to transfuse successfully with either red blood cells or platelets. Alternate therapies include high-dose immune globulin, cyclosporine, splenectomy, and low-dose radiation therapy to the spleen.[10] Tumor lysis syndrome is an uncommon complication (presenting in 1 out of 300 patients) of chemotherapy for patients with bulky disease.[11]

About 1% of morphologic CLL cases express T-cell markers (CD4 and CD7) and have clonal rearrangements of their T-cell receptor genes. These patients have a higher frequency of skin lesions, more variable lymphocyte shape, and shorter median survival (13 months) with minimal responses to chemotherapy.[12]

References

1. Keating MJ: Chronic lymphocytic leukemia. Semin Oncol 26 (5 Suppl 14): 107-14, 1999.  [PUBMED Abstract]
   
   
2. Faguet GB: Chronic lymphocytic leukemia: an updated review. J Clin Oncol 12 (9): 1974-90, 1994.  [PUBMED Abstract]
   
   
3. Chemotherapeutic options in chronic lymphocytic leukemia: a meta-analysis of the randomized trials. CLL Trialists' Collaborative Group. J Natl Cancer Inst 91 (10): 861-8, 1999.  [PUBMED Abstract]
   
   
4. Zwiebel JA, Cheson BD: Chronic lymphocytic leukemia: staging and prognostic factors. Semin Oncol 25 (1): 42-59, 1998.  [PUBMED Abstract]
   
   
5. Intravenous immunoglobulin for the prevention of infection in chronic lymphocytic leukemia. A randomized, controlled clinical trial. Cooperative Group for the Study of Immunoglobulin in Chronic Lymphocytic Leukemia. N Engl J Med 319 (14): 902-7, 1988.  [PUBMED Abstract]
   
   
6. Griffiths H, Brennan V, Lea J, et al.: Crossover study of immunoglobulin replacement therapy in patients with low-grade B-cell tumors. Blood 73 (2): 366-8, 1989.  [PUBMED Abstract]
   
   
7. Weeks JC, Tierney MR, Weinstein MC: Cost effectiveness of prophylactic intravenous immune globulin in chronic lymphocytic leukemia. N Engl J Med 325 (2): 81-6, 1991.  [PUBMED Abstract]
   
   
8. Robertson LE, Pugh W, O'Brien S, et al.: Richter's syndrome: a report on 39 patients. J Clin Oncol 11 (10): 1985-9, 1993.  [PUBMED Abstract]
   
   
9. Mauro FR, Foa R, Cerretti R, et al.: Autoimmune hemolytic anemia in chronic lymphocytic leukemia: clinical, therapeutic, and prognostic features. Blood 95 (9): 2786-92, 2000.  [PUBMED Abstract]
   
   
10. Rozman C, Montserrat E: Chronic lymphocytic leukemia. N Engl J Med 333 (16): 1052-7, 1995.  [PUBMED Abstract]
    
    
11. Cheson BD, Frame JN, Vena D, et al.: Tumor lysis syndrome: an uncommon complication of fludarabine therapy of chronic lymphocytic leukemia. J Clin Oncol 16 (7): 2313-20, 1998.  [PUBMED Abstract]
    
    
12. Hoyer JD, Ross CW, Li CY, et al.: True T-cell chronic lymphocytic leukemia: a morphologic and immunophenotypic study of 25 cases. Blood 86 (3): 1163-9, 1995.  [PUBMED Abstract]
    
    

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