The present invention provides a STAT3/5 activation inhibitor containing an aromatic compound represented by the general formula or a salt thereof as an active ingredient:Wherein X1 represents a nitrogen atom or a group —CH═, R1 represents a group —Z—R6, in which Z represents a group —CO—, a group —CH(OH)— or the like, R6 represents a 5- to 15-membered monocyclic, dicyclic or tricyclic saturated or unsaturated heterocyclic group having 1 to 4 nitrogen atoms, oxygen atoms or sulfur atoms, R2 represents a hydrogen atom or a halogen atom, Y represents a group —O—, a group —CO—, a group —CH(OH)— or a lower alkylene group, and A represents a group
