Soy Isoflavones in Treating Patients With Recurrent Prostate Cancer or Rising Prostate-Specific Antigen

Inclusion Criteria

• •Have histologically confirmed prostate cancer.
• •Have completed primary therapy (radical prostatectomy, external beam radiation, brachytherapy) for prostate cancer. "Watchful waiting" patients will also be eligible.
• •Have either two consecutive rises in prostate specific antigen (PSA) or a series of at least four PSA's over two years where the PSA doubling time is at least 3 months following a nadir response to localized therapy. The minimum PSA for this study is 0.2 ng/dL.
• •Not be receiving ongoing chemotherapy, radiation therapy or biological therapy for internal malignancy including prostate cancer.
• •At time of entry, the clinical team expects that no additional interventions for prostate cancer therapy (hormonal, chemotherapy, radiotherapy, etc.) will be necessary over the next 5 months.
• •Not be currently using Finasteride, androgens, or other PSA modifying hormonal agents. Utilizing prescription medications for urinary outlet obstructive symptoms will not be permitted. The use of non-prescription substances to improve urinary tract symptoms will not be permitted (i.e. Saw Palmetto, other herbal, alternative products).
• •Have kidney and liver enzymes within normal limits. Men with kidney and liver enzymes that are slightly elevated (\< 1.5 times the upper normal limit), but have been stable for several months particularly those that are related to a known disorder (such as Gilberts syndrome, past history of alcohol, hepatitis, or a history of non-alcoholic steatohepatitis) will be permitted to participate after clinical evaluation by the study physician."
• •Have no history of malabsorptive disorders or other metabolic disorders requiring special diet recommendations. Diabetics will be permitted to participate.
• •Voluntarily agree to participate and a sign an informed consent document.
• •Agree to consume a standardized vitamin and mineral supplement and avoid other nutrition, dietary, or alternative medications/supplements for the duration of the study.