PROBLEM TO BE SOLVED: To provide pharmaceutical compositions for treating breast cancer.SOLUTION: The pharmaceutical compositions for treating breast cancer of the invention are obtained from an extract of fruit body or mycelium of Antrodia camphorata, which comprises a first agent including at least dehydroeblicoic acid (DeEA), 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 breast cancer or prevention or reduction of breast cancer metastasis compared to single administration of the first or second agent.SELECTED DRAWING: None【課題】乳癌の治療に用いられる医薬組成物を提供する。【解決手段】乳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、少なくともデヒドロビリコ酸（ＤｅＥＡ）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、乳癌の治療若しくは乳癌転移の防止又は低下に相乗効果を発揮する。【選択図】なし
