It's a cancer...

Well, recently, i read many sentences in many kind of sites on internet.
And i found a common thing in every sentences i found, almost of it said "it give me a cancer" or "it is a cancer for me" or "oh no, cancer !" and so on.

I tried to figure what does it mean. And my thought is right.

"it give me a cancer" is not literally happened, it is a kind of idioms that express more than just "i can't get it out of my mind" or "it is really intrigues me in joy so i can't even have a day without thinking about it" or so on, but also (if the object is painting) "i can't get it out of my mind and i want to see it again, and again".

yes, that is a - not literally- cancer.