Recent　scientific　advances　have　increased　our　understanding　of　the　cancer　metastatic　complexities　and　provided　further　impetus　for　new　combination　therapies　to　prevent　cancer　metastasis.　Here,　we　demonstrated　that　a　combination　(HAMPT)　of　aspirin,　lysine,　mifepristone　and　doxycycline　can　effectively　and　safely　prevent　cancer　metastasis.　The　pharmaceutically-formulated　HAMPT　inhibited　adhesion　of　cancer　cells　to　either　endothelial　cells　or　extracellular　matrix　via　down-regulating　cell　adhesion　molecules　ICAM-1　and　alpha(4)-integrin.　HAMPT　inhibited　the　cloak　effect　by　activated　platelets　on　cancer　cells,　thereby　interfering　adhesion　and　invasion　of　cancer　cells　to　the　underlying　stroma.　At　the　effective　concentration,　HAMPT　induced　cancer　cells　into　dormancy　with　minor　inhibition　on　cell　viability.　Four-day　pretreatment　followed　by　30-day　oral　administration　of　HAMPT　(33.5-134　mg/kg)　to　the　mice　inoculated　with　cancer　cells　produced　significant　inhibition　on　cancer　metastasis　dose-dependently　without　marked　side　effects.　Fifty-day　rat　toxicity　study　with　HAMPT　at　doses　(335-1340　mg/kg)　20-fold　higher　than　its　therapeutic　dose　produced　no　significant　toxicity.　Interestingly,　the　acute　toxic　death　could　not　be　reached　at　the　maximum　administrable　dose　(5　g/kg).　This　proof-of-concept　study　provides　the　first　conceptual　evidence　that　cancer　metastasis　can　be　controlled　by　using　affordable　old　drugs　to　restrain　circulating　tumor　cells　from　gemmating　on　the　metastatic　soil　without　the　need　for　cytotoxicity.