He didn't defeat cancer, he got the best treatment and thankfully he was lucky it worked.
I know what you're saying but in fairness I think 'beat cancer' is just a turn of phrase that many would use for simply surviving it. That it's spun as a motivational slogan is another thing, and no great evil imo. Again, I'd cut him some slack on that one.
Indeed, I seem to recall (perhaps from one of his books) him acknowledging the situation as it was. He didn't 'fight it', that he just slept when he was tired, that he was lucky. I think you can rightly accuse him of many things but not necessarily for claiming to have kicked cancer's arse in anything other than a motivational sense.
As I said upstream, I like to keep the two Armstrong's (cancer survivor and cyclist) separate. I don't hate him that much to start deriding everything he's done.