For years it was believed that there must be some connection between breast and thyroid cancer, but research has proven this not to be the case. And though a woman may end up diagnosed with both over time, it is not because one causes the other, though both are considered endocrine-related cancers (hormone related). It is simply the fact that breast as well as thyroid cancers are cancers that commonly effect women.
There is one exception, however, that does link these two cancers “together.” That exception is having had radiation as a child. For adults who survived a childhood cancer that involved mantle radiation (radiation to the torso, and commonly including the neck area), their developing breasts, as well as the thyroid gland, were also exposed to high doses of radiation. This radiation, though clearly needed to save the life as the child, can later in life cause cancer to form in either or both areas.
Adults who as children had radiation of the adenoids also have a higher risk of developing thyroid cancer in later adult years, too. (People who are now in their late 60s or 70s today may have received radiation to the adenoids as children, rather than having them surgically removed.)
So it is important to know your childhood medical history. It is also important to be aware that half of men and one-third of women will develop some form of life-threatening cancer in their lifetimes. Sad but true.
These thyroid cancers happen fairly commonly. So make sure when you are seeing your doctor for your annual physical (yes, you should be going annually!) to have the doctor check your throat area as well as your breasts. Also report any changes that you may have personally noticed (like your necklaces fitting more tightly than usual).