The invention relates to a composition for treating or preventing prostate cancer or the recurrence thereof； including a non-aqueous extract of non-germinated broccoli seeds of the Brassica Oleracea Italica variety that are rich in sulforaphane. The extract is encapsulated by a compound selected from the group including acacia gum, maltodextrin, and the mixture thereof, and said composition can be provided in the form of a capsule, tablet, sugarcoated tablet, or film-coated tablet, and is orally administered one to three times a day at a daily dose of 2 to 200 mg.
