I don't think I do, so I'll give you the links and the brief version of the rebuttal.
My mother knows this woman through a business connection. Her story is true. It is not the whole story.
It is true that many Canadians wait for care. Some of those waits are fine, as mine were. Some are not. That's unfortunate, and the government is working at reducing it.
However, the fact is, this happens extremely rarely. I'd like to see the stats on how often patients with brain cancer die without ever getting the opportunity for aggressive treatment in the U.S. I can guarantee it would be more often than here, and here's why.
In the U.S., if you lose your health insurance after having cancer, you're uninsurable. That means if your cancer comes back, you're dead. What this woman isn't saying is that her follow-up care, and her care if her cancer comes back, will still happen for free. She was diagnosed here. She had no medical debt before this happened, no co-pays. She runs her own small business and has not had any supplemental insurance for a long time because of that (or if she did, she bought it separately) but the cost was likely about fifty dollars a month for her dental, drug plan, and whatever other supplemental health services she chose to get on it. Her babies were born in a Canadian hospital and she never paid a cent to a doctor or other practitioner for that to happen.
It's likely that a person in her position in the U.S. wouldn't have had much health insurance, because nobody in her family had the kind of job that would have provided it, and the insurance available for those who aren't getting it through their work is, I understand, nowhere near as good. She wasn't rich - just comfortably middle-class. So there's a decent chance that, had she lived in the U.S. with other details much the same, she wouldn't have been able to get the loans she took out to go to Arizona and get that treatment. And she wouldn't be able to sue anyone to get that money back later, as she's doing now. (She's suing the government to get her money back, and she's probably going to win.) And of course, she'd be waiting for the next bout of cancer, knowing that it would not only kill her, it would finish bankrupting her family.
Very few treatments are denied outright. A few new or experimental treatments for certain types of cancer are not yet covered by OHIP, usually because the drugs are extremely expensive and not yet proven. Her treatment was not denied - it was delayed. It's a gross exaggeration to imply that it happens often.
The last problem with the ad is that Obama isn't proposing Canadian style health care. He's proposing a model that will make a public option available alongside the private option that will remain available. So people who believe their insurance company is doing just fine for them have the option to stay. If you're happy with your health care? Don't change anything. If you're not? You may just survive if you get brain cancer, and you may not have to bankrupt yourself to do it.