Molds that grow on bread or food in the refrigerator are vanishingly unlikely to produce aflatoxin, the carcinogen you're referring to here. The real risk of food-borne illness from moldy kitchen foods are allergic or bacterial.
There are dozens of toxins harmful to humans that can be identified in different types of mold, of which there are many. Some have been known to raise the risk of tumors. One specific example is ocratoxin.
I did not mention aflatoxin because it is bad for you on a whole other level. Fortunately it's not very common.
