OK...
So this looks as if it's some dubious attempt to scare omnivores into becoming herbivores by telling them they consume unpleasant things. Eat meat and you could be eating cancer! Icky icky ick ick!
Well yes, but so what? Cancer is famously non-contagious (unless you're a dog), so what does it matter if you eat it? Also, plants can get cancers — they're called galls. So even if you keep off the lamb chops, you're still not safe from Eating Cancer.
This is irresponsible advertising. I'd complain to the Advertising Standards Authority if I didn't think the resulting publicity would spread the panic among gullible people further.