PROBLEM TO BE SOLVED: To provide pharmaceutical compositions for treating prostate cancer.SOLUTION: The pharmaceutical compositions for treating prostate cancer of the invention are obtained from an extract of the fruit body or mycelium of Antrodia camphorata, which comprises a first agent including at least Antocin K (AnK), and a second agent including at least Antroquinonol B (AnQB). When both of the first and second agents are administered, a synergistic effect is observed for treatment of prostate cancer or prevention or reduction of prostate cancer metastasis compared to single administration of the first or second agent.SELECTED DRAWING: None【課題】前立腺癌の治療に用いられる医薬組成物を提供する。【解決手段】前立腺癌の治療に用いられる医薬組成物は、ベニクスノキタケの子実体又は菌糸体の抽出物から獲得され、少なくともアンクチン酸K(AnK)を含む第1の薬剤と、少なくともアントロキノノールB(AnQB)を含む第2の薬剤と、を含む。前記第1の薬剤又は前記第2の薬剤の単独投与に比べ、前記第1の薬剤及び前記第2の薬剤の両方が投与された場合、前立腺癌の治療若しくは前立腺癌の転移の防止又は低下に相乗効果を発揮する。【選択図】なし