The present invention provides a pharmaceutical composition for treating prostate cancer in a subject in need thereof, which comprises a first agent comprising at least a Anctin K (AnK)； and a second agent comprising at least an Antroquinonol B (AnQB)； as well as each of them can be obtained from the extractions of a fruiting body or a mycelium of Antrodia camphorata wherein the first agent and the second agent shows synergistic effect for use in the treatment of prostate cancer or to prevent or to reduce the risk of a prostate cancer metastasizing, compared to administration of the first agent or the second agent alone.
