Our results also demonstrate that, this increase in Annexin-V can be measured in tumor in vivo in a preclinical model of breast adenocarcinoma with radiolabelled 99mTc-HYNIC-Annexin V. This tool could represent a reliable way to monitor early apoptosis induced by anticancer agents in order to evaluate early treatment efficacy and allow improvement of therapeutic strategies. This evidence concerns the gene ANXA5 and neoplasm.