Please can someone put my mind at rest

Hi I have TNBC,diagnosed over 2 years ago had chemo and radiotherapy and operation then got the all clear.Have just found out it's come back again,they said I can start chemo next week to shrink it but they won't be able to give me surgery after as it's too deep in chest wall.Has anyone else had this, if they shrink it how can they keep it at bay.