Hi. I am not a nurse, but I had thyroid cancer five and a half years ago. Given that you are having RAI, I assume you have one of the two less serious forms of thyroid cancer, papillary or follicular.

From what I have read and what my team told me, there is a chance that RAI can slightly increase our risk of certain other cancers, but it sounds like it is a case of if the general population have a 1% chance of one of those cancers, we might have a 1.5% chance. Given that thyroid cancer is a relatively mild cancer and that most people are at fairly low risk of reccurence, I am assuming they would not risk doing RAI if it greatly increased the risk of more serious cancers.

And yes, thyroid cancer can come back, but for most people, the risk is low. Unless you were told you were at particularly high risk (like if you have been told your cancer has spread to your lungs or bones or something), then the odds are the highest risk of reccurence you are likely to have is 20% and it could be significantly lower.

As well as that, one of the studies I read said that most recurrences are in the lymph nodes and that those are "only a nuisance." I mean, obviously, none of us wants to deal with recurrence and I do get moments before I go in to get my results for my yearly scans and so on where I think, "oh gosh, what if it has come back? I really don't want to have to deal with all that again!" but I generally work on the premise that I'll worry about it if it does. The odds are against it and even if it does come back, it's not likely to be any worse than it was the first time around.

The worst is probably over for you now too.

I will say my first year or so after having thyroid cancer, I was...sort of waiting for the other shoe to drop, thinking "I've had cancer. It can't be this easy" (by the standards of cancer, obviously; it isn't easy by normal standards but compared to what one hears about people going through other cancers).