Hi @Pearl - there have been a few comments about thyroid on the blog in the last 12 months or so - but I don't think there is any link to Breast Cancer or chemo/rads or tabs. It is not uncommon in women.
An interesting point - my Breast Cancer surgeon is a specialist in BC and thyroid ......and a buddy who had BC also had thryroid problems (ongoing.)
Here is a link to some research on the matter!
https://breast-cancer-research.biomedcentral.com/articles/10.1186/s13058-019-1122-3All the best to you xx