Paget's of nipple and other areas of breast

I had a stage one, invasive ductal tumor removed in September 2023. It was 3 mm in size, no node involvement and clean margins. It actually was completely removed with the biopsy it was so small. Been on AI since. Less than a month ago I noticed nipple on opposite breast receding to areola. No pain or redness then. Now a small fissure which is sore to touch. Waiting to see dermatologist for her opinion and hopefully biopsy. I say this because in December of 2023 I had a ctDNA blood test which showed positive, meaning I have cancer DNA floating around. May be related to this new issue. Had PET scan and looks ok. MRI at end of month. Genetic testing shortly after surgery showed nothing. Another round of waiting!

I have been diagnosed with Paget's disease. As usual for this, I initially saw a primary care physician, nipple itch treated with surface ointment, then a mammogram with negative results in November, but my dermatologist biopsied the rough spot and called me a week later, in mid January with diagnosis. And so rare, but fortunately caught early, because of a dermatologist who muttered, "I've heard of a breast cancer that shows up on the skin...." I'm telling everyone to have a dermatologist on speed dial! All I had was an itchy nipple. No discharge, no lump. But I have fibrocystic breasts, so Mayo ordered an MRI, then an MRI with biopsy to the cysts lurking in a nearby mass, but THAT came back benign, surprising to all of us. Scheduled for another MRI with biopsy closer in, just to be sure, but still stage zero, and removal of nipple scheduled approximately next month. No BRCA gene evidence, no reason to remove entire breast, although initially, I was ready for that and today was supposed to be that surgery day.
What will be the upcoming course? Meds? Radiation?
This is so rare, 1%, that many friends are surprised too, their breast cancers have been extensive and, in the last 6 months, I've lost 2 friends to metastasized breast cancer. Trying not to obsess, but information is lacking.
Where did this come from? I've had melanoma in situ, and many basal cell cancers removed, both genetic and curse of living in sunny Arizona. I'm a 67 year old hat lady, long sleeves and pants, even in summer. What else can I do?

Had biopsy done on left breast nipple by dermatologist which fortunately showed only a small fibroma, benign. Whew! mRI done and nothing showed up on either breast. Will have 6 month follow ups, either mammogram or MRI. Had second ctDNA test and was slightly increased ☹️ Not sure what will happen with this information as little information is out there on ctDNA and oncologist not sure how to monitor. Suppose I will keep getting blood tested for some time to see if it relatively stable or spikes which probably would indicate a recurrence and then have PET scan. This is a hard hard journey!