I have not seen this data - even in women treated with I-131, there is not a documented inc'd risk of ovarian CA. This may have been a small study or otherwise flawed, but if this is a true association, more research needs to be done.
I never read that one but did a search and you are correct.
There are other factors involved so don't sweat it. If you don't have any other risk factors I would not lose any sleep over it.
In addition to hyperthyroidism, what are some of the risk factors for ovarian cancer?
Having a close relative - mother, sister, daughter - with breast, ovarian or colon cancer.
A history of breast, endometrial, or colon cancer.
Uninterrupted ovulation (infertility, never used birth control pills, never been pregnant.
Increasing age.