I had a stage 1A ER+, PR+, HER2- tumor lumpectomy removed last year so it's a simpler cancer in a sense. My follow-up instructions are to do self-exam every month or more frequently, have a physician-assisted breast check (ob/gyn or anyone doing a lot of such exams) every six months and annual mammo and ultrasound followed by check-up with both my oncologist and breast surgeon. And bloodwork including tumor markers. Maybe you get a physician breast check more frequently, at least for the first few years?