The present invention provides a method for treating cancer using a human folate receptor [alpha] (referred to herein as FOLR1) targeted drug by increasing the expression of FOLR1 using an antifolate, a cancer drug including a human FOLR1 targeted drug for increasing the expression of FOLR1 using an antifolate, and a method for enhancing the therapeutic effect of a human FOLR1 targeted drug by increasing the expression of FOLR1 in cancer cells using an antifolate. For example, the present invention provides a more effective method of treatment for cancer patients having a low FOLR1 expression level in whom the antitumor activity of human FOLR1 targeted drugs is not adequately manifested, and cancer patients who express FOLR1 but desire enhanced cancer treatment, by the concomitant use of an antifolate and a human FOLR1 targeted drug.本發明提供一種利用人類FOLR1標靶藥之癌症之治療方法、包含人類FOLR1標靶藥之癌症之醫藥、及增強人類FOLR1標靶藥之治療效果之方法，上述利用人類FOLR1標靶藥之癌症之治療方法係使用葉酸代謝拮抗劑而使葉酸受體α(folate receptor α，以下簡寫為FOLR1)之表現增加，藉此利用人類FOLR1標靶藥治療癌症；上述包含人類FOLR1標靶藥之癌症之醫藥係用以使用葉酸代謝拮抗劑而令FOLR1之表現增加；上述增強人類FOLR1標靶藥之治療效果之方法係使用葉酸代謝拮抗劑而使癌細胞之FOLR1之表現增加，藉此增強人類FOLR1標靶藥之治療效果。例如，本發明提供一種針對FOLR1之表現量較低且未充分發揮人類FOLR1標靶藥之抗腫瘤活性之癌症患者、或者欲進一步增強表現FOLR1之癌症的治療之癌症患者，藉由併用葉酸代謝拮抗劑與人類FOLR1標靶藥而更有效之治療方法。
