BC in supernumerary nipple

Hi
I had BC in my 3rd nipple which was under my breast bone. Surgeon says fairly unusual. Large lump was removed plus nipple. Told the op was like having a mastectomy but I was so fortunate not to need my actual breast removed.
I’m unable to have radiotherapy as it may destroy other organs due to where cancer was.
I’m on letrozole but hating the side effects.
Anyone else had BC in 3rd nipple? Xx