DISEASE CHARACTERISTICS:

• Diagnosis of chronic lymphocytic leukemia (CLL) of any stage as defined by the following:

  • Peripheral blood absolute lymphocyte count greater than 5,000/mm^3 within 14 days prior to study
  • Lymphocytes must be small to moderate size with no more than 55% prolymphocytes, atypical lymphocytes, or lymphoblasts morphologically
  • Phenotypically characterized as B-CLL

• Must have one of the following characteristics indicating need for chemotherapy:

  • Progressive marrow failure (hemoglobin less than 10 g/dL and/or platelet count less than 100,000/mm^3)
  • Progressive lymphocytosis with an increase of more than 50% over a 2 month period or anticipated doubling time of less than 6 months
  • Massive (i.e., greater than 6 cm below left costal margin) or progressive splenomegaly
  • Massive nodes or clusters (i.e., greater than 10 cm in longest diameter) or progressive adenopathy
  • At least 10% weight loss within 6 months of study
  • Extreme fatigue
  • Fevers greater than 100.5 degrees F for 2 weeks without evidence of infection
  • Night sweats without evidence of infection
• No autoimmune anemia or autoimmune thrombocytopenia

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• See Disease Characteristics

Hepatic:

• Bilirubin no greater than 2 mg/dL unless secondary to tumor

Renal:

• Creatinine no greater than 2.0 mg/dL
• Creatinine clearance at least 40 mL/min if creatinine is greater than 1.5 mg/dL

Other:

• No other prior or concurrent malignancy within the past 2 years except basal cell carcinoma of the skin or carcinoma in situ of the cervix
• No active infection requiring oral or intravenous antibiotics
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior cytotoxic chemotherapy

Endocrine therapy:

• No prior steroid treatment for CLL

Radiotherapy:

• Not specified

Surgery:

• Not specified