Dietary administration of mushroom mycelium extracts in patients with early stage prostate cancers managed expectantly: a phase II study.

OBJECTIVE To assess the efficacy and safety of dietary supplements in patients with early stage prostate cancers who are managed expectantly. METHODS Seventy-four patients with early prostate cancer, who were treated with expectant management, enrolled in the study. A mushroom mycelium extract was given at a dose of 4.5 g/day for 6 months. The primary endpoint was the proportion of patients in which the prostate specific antigen level decreased by 50% or more following treatment. The adverse events, change of prostate specific antigen value and quality of life were also evaluated. RESULTS In only one of 74 patients (1.4%), the prostate specific antigen value decreased more than 50%. Grade 2 diarrhea and grade 1 itching were observed in one patient, and patient ingestion compliance was maintained near 100%. The alternation of prostate specific antigen values was stable before and after treatment. In subjects with strong anxiety prior to supplement ingestion, these feelings were significantly alleviated (state anxiety, P = 0.0018; trait anxiety, P = 0.0099). CONCLUSIONS In this phase II study of early prostate cancer patients who were managed expectantly, a mushroom mycelium extract was an ineffective treatment for reducing 50% or more the patient prostate specific antigen values.