The spread of cancer from its original site to distant organs—the primary reason cancer becomes life-threatening.Metastasis is the multistep process by which cancer cells disseminate from the primary tumor to establish secondary tumors at distant sites. Steps include local invasion, intravasation, circulation, extravasation, and colonization. Integrins, matrix metalloproteinases, and VEGF-mediated angiogenesis are key mediators. Anti-metastatic peptide strategies include integrin inhibition (cilengitide targeting αvβ3), CXCR4 antagonism (motixafortide disrupting CXCL12-mediated homing), and anti-angiogenic approaches.