This invention provides a medicament for the treatment of cancer,which cause a reduction of cancer. This invention relates to use of acompound which has inhibitory activities against prostaglandin E2 receptor(EP4 receptor) and is represented by the following general formula (I), (II),(III), or (IV), or a pharmaceutically acceptable salt thereof, or apharmaceutical composition comprising the compound or the salt for themanufacture of a medicament for the treatment of cancer. The inventionrelates to a method for treatment of cancer comprising administering thecompound or a pharmaceutically acceptable salt thereof, or apharmaceutical composition comprising the compound or the salt to humansor animals. The compound or a pharmaceutically acceptable salt thereof, orthe pharmaceutical composition may be used in combination with one ormore second active agents.(see formula I) (see formula II) (see formula III) (see formula IV)
