Cancer is a disease that has many forms, so to cure it you need a different "anti-agent" as you call it for each form. Some cancers are age-related, others are not, each occurs via a different pathway. I totally doubt that one magic bullet will cure all cancers. That is why despite many millions of dollars/pounds being funneled into cancer research each year there has been no "cure" for cancer. Indeed you could argue that this money might be better spent researching diseases we know might give a better "return" but are sidelined for the more politically correct diseases such as cancer. Sorry to be cynical but that's the way it is.