If tumor markers are elevated does it mean tamoxifen isn't working? dr. wants to recheck in two weeks. what is next? had recon surgery in december.

Check again: Not sure what "recon surgery" means but please do not take an elevated tumor marker as a certainty for cancer. You did not say how much it went up but remember there can be lab errors and even if it's a true elevation, it may not have any meaning. A tumor marker can go up for other reasons. I see nothing wrong with repeating one in a short interval. Hope it all goes well.