RATIONALE: Drugs used in chemotherapy, such as fludarabine and cyclophosphamide, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. It is not yet known whether giving fludarabine together with cyclophosphamide is more effective than fludarabine alone in treating chronic lymphocytic leukemia.

PURPOSE: This randomized phase III trial is studying giving fludarabine together with cyclophosphamide to see how well it works compared to fludarabine alone in treating patients with advanced chronic lymphocytic leukemia.

OBJECTIVES:

Primary

• Compare the progression-free survival, as well the overall survival and duration of remission in patients with previously untreated, advanced chronic lymphocytic leukemia treated with fludarabine with versus without cyclophosphamide.

Secondary

• Compare the incidence of side effects and quality of life of patients treated with these drugs.

OUTLINE: This is a multicenter, randomized study. Patients are randomized to 1 of 2 treatment arms

• Arm I: Patients receive fludarabine IV on days 1-5.
• Arm II: Patients receive fludarabine IV and cyclophosphamide IV on days 1-3. In both arms, treatment repeats every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity.

PROJECTED ACCRUAL: A total of 375 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Confirmed diagnosis of previously untreated chronic lymphocytic leukemia (CLL)

  • Binet stage C and stage B are acceptable if there is rapid disease progression, symptoms of enlarged lymph nodes and organs, or severe B-symptoms
  • Binet stage A is acceptable, if there are B-symptoms

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Life expectancy > 6 months
• No severe organ dysfunction
• No other previous or concurrent neoplasms, autoimmune hemolytic anemia, or thrombocytopenia

PRIOR CONCURRENT THERAPY:

• No prior or concurrent chemotherapy