Question about local recurrence

Angel84

I am concerned about my mother. She was diagnosed with Stage 1 breast cancer 2.5 years ago, and she had mastectomy. A month ago she had examination but doctor didn't check her breasts since she had mammography of other breast and lung scan and that was fine. Her next appointment with doctor who should check her breast is over a month from now and she told me that she felt something hard above her scar. But she doesn't have idea if that thing was there before or not, since she doesn't recall touching that spot before.

I don't know how these local recurrence show and is this something to be concerned about or not?

I also don't know would it be helpful for her to do tumor marker test CA 27-29...will it show if something is off?

Thank you