Which among the following is true statement regarding breast cancer metastasis?

Metastases occur after breast cancers acquire their own blood supply.(neovascularization). Thereafter, cancer cells may be shed directly into the systemic venous blood to seed the pulmonary circulation the axillary and intercostal veins or the veebral column Batson plexus of veins, which courses the length of the veebral column. These cells are scavenged by natural killer lymphocytes and macrophages. 60% of the women who develop distant metastases will do so within 60 months of treatment.