@Moosie - you haven't mentioned what type of massage so I can only assume it is medical related massage and that perhaps you have a fluid build up? Sorry, if I am on the wrong tram!
Look for a massage therapist who specialises in breast care, I saw a Remedial massage therapist recommended by my Physio - it may help if you have fluid build up that is slow to move along and just to get a little movement.
There is a fact sheet, link below from BCNA website - hope that helps
https://www.bcna.org.au/understanding-breast-cancer/resources/accessible-resources/lymphoedema/