You mention that you are currently undergoing breast reconstruction. My CA 27.29 showed an increase when I had my bloodwork done in December 2020 for my January appointment in January 2021. I have also been doing breast reconstruction....diep, no implants...and had had my bloodwork done one week after my final surgery (constructing my new nipples...a pretty simple surgery). At the January appointment, my oncologist showed some concern about the rise in CA 27.29 (not a significant increase as yours was) and asked if I had had surgery recently because surgery causes inflammation and inflammation can cause tumor markers to rise. I just had the CA 27.29 done for my appointment on 5/10/2021 and they have dropped considerably. Also, it is my understanding that it is more common for women to have an infection after reconstruction with implants vs diep flap (using the body’s own tissue). Infection also causes inflammation. Perhaps your reconstruction process has affected your tumor marker readings. It is all very scary.