The present invention relates to the use of at least one antibody, or a functional fragment thereof, which is capable of binding to the CD151 protein and thereby inhibiting tumour growth, in the preparation of a medicament intended for the early treatment of cancer. The invention is also directed to a composition for the treatment of cancer, comprising, as active ingredient, at least one anti-CD151 antibody, or a functional fragment thereof, which is capable of binding to the CD151 protein and/or inhibiting its metastasis-promoting activity, said antibodies consisting of antibodies secreted by the hybridoma deposited at the ATCC under number CRL-2696.