What was the progression of your mets?

[GZM]

I've been a lurker but this is my first post.

I was dx'ed with a recurrence in my brain only at the beginning of the year. I read that brain as the first/only site of mets was becoming more common due to the targeted therapies killing the cancer in the body but the escaped cells squeezing through the BBB. Well my body scans were clear for months but the last one showed something in my liver. My onc isn't jumping to the conclusion that's it's mets but agrees it's suspicious because it's new.

If it is mets, is it more likely a) the cancer squeezed its way back through the BBB or b) there was cancer there all along but since I was on systemic treatment for 7 months, it wasn't big enough to show up until I took a break from systemic treatment? Brain as the first/site of mets is still unusual enough that I haven't found anyone else in the same situation.