In his new book, “This is Herman Cain!: My Journey to the White House,” the Republican candidate competitor opens up about his battle with stage four colon and liver cancer, noting that oncologists gave him  a 30 percent chance of survival.

He said doctors called him a “cancer miracle,” and Wednesday  Cain told George Stephanopoulos on “Good Morning America”  that he was willing to release his medical records to reassure voters that he was physically fit to be president.

“I’m willing to release my medical records,” Cain told Stephanopoulos.  ”Two months ago, George, I went to see my oncologist in Atlanta, got a full-scale check-up, CAT scan, X-rays, all of the various blood tests, and he put it in writing that, after five years, I am now totally, 100 percent, cancer-free.”

Cain’s decision to disclose his medical records may not have come from him alone but  in response to Frank Schwerin, the chairman of the Collier County Republican Executive Committee in Florida, who implored Cain to hand his records over.

“Fast forward six months, eight months. If he’s our nominee, they’re going to be demanding that, and if he withholds it, there will be questions,” Schwerin told ABC News’ affiliate WZVN. “I think it has to be addressed before we start voting on him.”

Without having seen Cain’s medical records, doctors hesitated to discuss his medical status and diagnosis. Nevertheless, while the term “miracle” is often thrown about  in cancer-survival stories, medical experts said Cain’s survival could be attributed to cancer treatments that have become more personalized and focused on long-term care.

“This is not a miracle but an example of the evolving importance of a personalized view of a clinical problem, even cancer,” said Dr. Joel Levine, founding director of  Colon Cancer Prevention Program at the University of Connecticut. “Personal really means individualized, suggesting that doing molecular profiling of cancers can guide therapy. This is a rapidly evolving approach and will be followed by identifying risks prior to cancer and methods to lower them in any number of ways.

“In simple terms, cancer is not a one size, or one outcome, fits all,”  Levine continued. “The goal will be to find more cases like Mr. Cain. It is not divine per se but a window to a better understanding of how cancers behave.”