Welcome to Healthcare-Magic
Thanks for the query.
Well,positive pet scan is a bad sign but it still doesnt mean that there is cancer recurence since lot of pets scan results are false positive. However since this was stage 3 and there is breast swelling and lymh node enlargement,I am afraid that this may be cancer and you need to wait biopsy
and start treatment right after it. YOu ll probbaly need both chemo and radiotherapy.
Wish you good health.