Yes, cancer is mutated DNA and aliens abduct people because they
cannot reproduce themselves , their genitals fell off a long time ago.

So they try to turn humans into aliens,the abduct humans and
impregnate them with alien DNA,  but their experiments are not
successful yet.

A fully grown cancer will be an alien being that will replace the
human.

So I recommend to destroy the aliens, then cancer will be gone
forever.