Why case-controlled study is more bias prone than cohort study?

Question

[CY]

I noticed from several articles saying that case-controlled study is more bias prone than cohort study (in the context of cancer early detection using molecular markers). I spent sometime to try to rationalize the idea (I guess it has something to do with case-controlled study having more risk of carrying confounders?) and could not figure out the logics. Can someone some comments on this?