RATIONALE: American ginseng extract may prevent or reduce acute respiratory illness in patients with chronic lymphocytic leukemia. It is not yet known whether American ginseng extract is more effective than a placebo in preventing respiratory infections.

PURPOSE: This randomized trial is studying the side effects of American ginseng extract and to see how well it works compared with a placebo in preventing respiratory infection and in reducing antibiotic use in patients with chronic lymphocytic leukemia.

OBJECTIVES:

Primary

• To assess the effect of American ginseng extract on the number of days of acute respiratory infection (ARI) during the peak respiratory illness season (January-March) in patients with chronic lymphocytic leukemia (CLL).
• To determine the safety of American ginseng extract in these patients evaluated according to NCI CTCAE v3.0.

Secondary

• To assess the effect of this treatment on antibiotic use days (AUDs).
• To assess the effect of this treatment on the rate of all infections diagnosed by a physician.
• To assess the effect of this treatment on the duration and severity of each ARI episode.
• To assess the effect of this treatment on major infections defined as infection severe enough to require hospitalization or intravenous antibiotics.
• To assess the effect of this treatment on the incidence of herpes zoster infection defined as an episode of physician-diagnosed zoster infection.
• To assess the effect of this treatment on CLL disease activity (i.e., serum IgG, total lymphocyte count, platelet count, and Rai staging).
• To determine the incidence of ARI and type of illness in an untreated cohort of CLL patients over an entire winter respiratory illness season (January 1- April 30).

Tertiary

• To determine the effect of this treatment on the incidence of influenza and respiratory syncytial virus confirmed by a physician.

OUTLINE: This is a multicenter study. Patients are stratified according to antibiotic prophylaxis with trimethoprim-sulfamethoxazole (yes vs no), serum IgG (≤ 500 mg/dL vs > 500 mg/dL), and influenza vaccine status (yes vs no). Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients receive oral American ginseng extract twice daily.
• Arm II: Patients receive oral placebo twice daily. Treatment in both arms continues for up to 4 months in the absence of illness or adverse events.

After completion of study treatment, patients are followed at 4 weeks by phone.

DISEASE CHARACTERISTICS:

• Diagnosis of chronic lymphocytic leukemia (CLL)

  • Phenotypic evidence (i.e., flow cytometry or bone marrow biopsy) of disease

• Untreated CLL allowed

PATIENT CHARACTERISTICS:

• ECOG performance status (PS) 0-2 OR Karnofsky PS 60-100%

• Life expectancy > 12 months

• Creatinine < 2.0 mg/dL OR creatinine clearance > 50 mL/min

• AST/ALT ≤ 2.5 times upper limit of normal (ULN)

• Total bilirubin ≤ 1.5 times ULN

• Not pregnant or nursing

• Fertile patients must use effective contraception prior to and during study treatment

• No known cirrhosis, collagen vascular disease, multiple sclerosis, or HIV positivity

• No other prior or concurrent malignancies except for non-melanoma skin cancers or carcinoma in situ of the cervix

  • Other prior malignancies allowed provided the patient has been disease-free for > 5 years

• No uncontrolled intercurrent illness including, but not limited to, any of the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia

• No psychiatric or social illness that would limit compliance with study requirements

• No history of allergy or other adverse response to ginseng products

• No history of seasonal or environmental allergies that require ongoing treatment with antihistamines, intranasal corticosteroids, or systemic corticosteroids

PRIOR CONCURRENT THERAPY:

• More than 3 months since prior and no concurrent chlorambucil
• At least 1 month since prior and no other concurrent herbal ginseng products
• No prior or concurrent fludarabine, alemtuzumab, rituximab, intravenous immunoglobulin, or hematopoietic stem cell transplantation
• No concurrent corticosteroids (20 mg/day of prednisone or equivalent)
• No concurrent antibiotic prophylaxis, except for trimethoprim-sulfamethoxazole
• No concurrent warfarin
• No other concurrent investigational or commercial agents or other therapies with the intent to treat the patient's malignancy