Green Tea Extract in Treating Patients With Stage 0, Stage I, or Stage II Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS:

Confirmed diagnosis of chronic lymphocytic leukemia (CLL)

Stage 0, I, or II disease
Previously untreated disease
Splenomegaly, hepatomegaly, or lymphadenopathy are not required for the diagnosis of CLL
Absolute lymphocyte count > 10,000/mm^3
Lymphocytosis must consist of small to moderate size lymphocytes, with ≤ 55% prolymphocytes, atypical lymphocytes, or lymphoblasts morphologically

Phenotypically characterized B-CLL defined by all of the following criteria:

A population of leukemic cells that co-expresses the B-cell antigen CD23 as well as CD5 in the absence of other T-cell markers (CD3, CD2, etc.)
Dim surface immunoglobulin expression
Exclusively κ or λ light chains
Mantle cell lymphoma must be excluded by demonstrating the absence of the t(11:14) by FISH testing

Patients who require chemotherapy for treatment of CLL, based on any of the following criteria, are excluded:

CLL-related symptoms requiring treatment, including any of the following:

Unintentional weight loss ≥ 10% body weight within the previous 6 months
Extreme fatigue
Fevers > 100.5°F for 2 weeks without evidence of infection
Night sweats without evidence of infection

Evidence of progressive marrow failure due to CLL involvement of bone marrow as manifested by the development of worsening anemia (hemoglobin < 11 g/dl) and/or thrombocytopenia (platelet count < 100,000/mm^3)

Thrombocytopenia due to immune phenomena (ITP) is permitted as long as platelet count is ≥ 100,000/mm^3and the patient is not on active pharmacologic therapy
Massive (i.e. > 6 cm below left costal margin) or progressive splenomegaly
Massive nodes or clusters (i.e., > 10 cm in longest diameter) or progressive adenopathy
Progressive lymphocytosis with an increase of > 50% over 2 month period, or an anticipated lymphocyte doubling time of < 6 months

PATIENT CHARACTERISTICS:

Platelet count ≥ 100,000/µL
ANC ≥ 1500/µL
Hemoglobin ≥ 11 g/dL
Total or direct bilirubin ≤ 1.5 x upper limit of normal (ULN)
AST (SGOT) and ALT (SGPT) ≤ 2 x ULN
Creatinine ≤ 1.5 x ULN OR creatinine clearance ≥ 40 mL/min
May have a history of autoimmune hemolytic anemia (AIHA) and positive Coombs test provided there has not been active hemolysis requiring transfusion or steroid treatment ≤ 10 weeks prior to registration
ECOG performance status 0, 1, or 2
Life expectancy of ≥ 6 months
No uncontrolled infection
No myocardial infarction within the past 6 weeks
No New York Heart Association class III or IV congestive heart failure
Not pregnant or nursing
Negative pregnancy test
Must employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device [IUD], or abstinence, etc.) prior to study entry and for the duration of study participation
No other severe medical or psychiatric illness
No active hemolysis requiring transfusion or other pharmacologic therapy

PRIOR CONCURRENT THERAPY:

At least 8 weeks since prior and no other concurrent over the counter green tea or green tea extract
No prior daily use of over the counter green tea products for medicinal purposes for > 4 weeks (phase II only)
No other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy considered investigational (utilized for a non-FDA-approved indication and in the context of a research investigation)
No concurrent combination anti-retroviral therapy for HIV positive patients
No concurrent oral steroid preparations