Sulforaphane in Treating Patients With Recurrent Prostate Cancer

PRIMARY OBJECTIVES: I. To determine the proportion of patients who achieve a 50% decline in prostate-specific antigen (PSA) levels within 20 weeks of sulforaphane treatment. SECONDARY OBJECTIVES: I. To determine the percentage change in PSA from baseline to the final measured value at the end of study as well as the maximal PSA decline that occurs while on study for each subject. II. To determine the proportion of patients whose PSA has not doubled after full 20 weeks of sulforaphane treatment. III. To determine the safety profile of sulforaphane. IV. To determine the pharmacokinetics (PK) of sulforaphane and its metabolites in blood. V. To determine the effect of sulforaphane supplementation on target pharmacodynamic (PD) modulation in peripheral blood cells. VI. To assess the effect of Glutathione-S-Transferase Mu 1 (GSTM1) genotype on sulforaphane PK, PD. VII. To collect frozen serum for future analysis of correlative biomarkers. OUTLINE: Patients receive sulforaphane orally (PO) once daily for 20 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 14-30 days and every 6 months for 12 months.