Green Tea Extract in Treating Patients With Monoclonal Gammopathy of Undetermined Significance and/or Smoldering Multiple Myeloma

OBJECTIVES: Primary * Conduct a pilot study investigating the effects of Polyphenon E, a compound extracted from green tea which contains epigallocatechin-3-gallate (EGCG), on monoclonal protein levels in patients with monoclonal gammopathy of undetermined significance and/or smoldering multiple myeloma. Secondary * Collect, process, and store blood and marrow specimens for future measurement of the biologic effects of Polyphenon E on the plasma cells of these patients by utilizing proteosome activity assays and gene expression profiling. OUTLINE: Patients receive oral green tea catechin extract (Polyphenon E) daily on days 1-28. Treatment repeats every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. Patients may undergo blood, urine, and bone marrow sample collection periodically for correlative laboratory studies. Samples are analyzed for monoclonal protein (M-protein) levels, proteosome function, and gene expression.