The invention concerns an inhibitor of the expression of chemokine CCL7 or an inhibitor of the expression of the receptor CCR3 or an inhibitor of CCL7/CCR3 interaction for the use of same to prevent or treat the extension of prostate cancer outside the prostatic capsule in a subject. The invention also concerns a method for determining the degree of aggressiveness of a prostate cancer tumour in a subject suffering from prostate cancer, comprising a step of determining the concentration or level of expression of the receptor CCR3 in a sample of prostate tumour cells obtained from said subject.
