MSNBC has pulled a vicious political commercial attacking Republican presidential nominee Sen. John McCain over his bouts with cancer and medical records. The network aired the 32-second commercial for two days, September 25-26, the day before and the day of the first presidential debate, according to an Associated Press article.

MSNBC stopped the ad on Friday, without specifying why, but not before it was seen by millions of viewers.

"The ad had not been thoroughly vetted prior to air, and has since been removed from our commercial rotation," NBC spokeswoman Allison Gollust said in an e-mail, but did not elaborate, according to the AP.

CNN refused to air the commercial, and Fox News commentator Bill O'Reilly said, of all the political ads this election season, this one was "perhaps the most vicious political ad of the campaign," according to the AP.

The last time McCain had cancer was 2002. But in the $50,000 ad, paid for by Brave New PAC and Democracy for America, a man identified as Michael D. Fratkin, MD, and another identified as Noah Craft, MD, PhD, told viewers that McCain could become incapacitated or die.

FRATKIN:  Another bout of cancer for John McCain while he's president of the United States would profoundly impact his capacity to lead.

CRAFT: Melanoma is the deadliest of skin cancers and the chances of survival if you have melanoma spread through your body is very, very slim.

The commercial concludes by misleading viewers by saying McCain has not been forthcoming with his medical history.

COMMERCIAL TEXT: "Why won't John McCain release his medical records?"

The truth is, according to the AP, McCain has released his medical records – he has voluntarily allowed reporters to study thousands of pages of his medical records. By contrast, Sen. Barack Obama has not.

In May, McCain provided 1,173 pages of medical documents to a small group of reporters to examine for several hours, but the campaign did not release the documents and reporters were not allowed to make copies. The records, which covered McCain's health history from 2000-2008, showed that he had his last episode of melanoma, the most dangerous form of skin cancer, six years ago.

The records described him as having a strong heart and generally good health. He gets an in-depth skin cancer check every few months.McCain's Democratic rival, Barack Obama, has not made his medical records public. His physician earlier this year released a one-page letter attesting to his good health.

Michael D. Fratkin, MD Internal Medicine Hospice and Palliative Medicine Eureka, California, posted a letter dated September 13, 2008, on Obama's website calling for McCain to release his medical records, despite having already done so. Fratkin acknowledges in the post that reporters have had the opportunity to study McCain's medical records, but he fails to point out that Obama has yet to release his.

FRATKIN: John McCain should [MUST] be held accountable by the American people and its agents, the free press, to release without restriction the entirety of his medical records. Any hesitation to do so would clearly imply that there are significant medical concerns about his ability to fulfill the duties of the President.

Fratkin apparently missed the irony of demanding McCain's medical records on Obama's website, while the freshman senator withholds his own.

CNN reported in May, 2008, that not only did Obama withhold his medical records, but he also would not allow his physician to speak to the press.

Obama released a one-page statement from his primary care physician. He did not release any medical records or make his doctors available to the media.