Afinitor (everolimus) is a cancer medicine that interferes with the growth of cancer cells and slows their spread in the body. Afinitor is used to treat certain types of kidney cancer, breast cancer, or brain tumor. Everolimus is usually given after other treatments have been tried without success. Afinitor is also used to treat certain types of advanced or progressive tumors of the stomach, intestines, or pancreas. Afinitor is also used to treat non-cancerous (benign) tumors of the kidney in people with a certain genetic condition called tuberous sclerosis complex.