"If the lesion was resectable [removable], I suspect it would have been resected at the time," Dr. James Watson, a surgical oncologist at Fox Chase Cancer Center in Philadelphia, Pa., told Dr. Tim Johnson, ABC News medical editor, on ABC News Now's Healthy Life program Tuesday.
"I suspect there was more than one lesion found."
According to figures from the National Cancer Institute, about half of all colon cancers eventually spread to the liver, either at the time the disease is first detected or as a result of disease recurrence.
So what are the chances that Snow will survive this repeat episode? The exact answer to this question is impossible to determine, as each individual and each case of cancer has a host of different characteristics that affect chances of survival.
But a comprehensive look at all recurrent cancer patients shows that the statistics are not promising.
"If a person develops a spread of colon cancer to the liver, the chances they can be cured by surgery and chemotherapy is between 25 and 40 percent," said Dr. David Schoetz of the Lahey Clinic in Burlington, Mass., and former president of the American Society of Colon and Rectal Surgeons.
"So I would say that Tony Snow is in pretty big trouble."
Watson agreed. "The odds are not in his favor for a 100 percent cure," he said.
Still, Schoetz said, Snow's situation is not hopeless. He added that though it is impossible to reliably predict the chances of survival for either Snow or Edwards, Snow's prognosis may well be better.
"If you had to pick, colon cancer recurrence is probably a little more curable than breast cancer recurrence," Schoetz said.
And Watson said recent advancements in treatment at least give Snow's doctors needed ammunition against the resurgence of his disease.
"We've made enormous strides in colon cancer in the last decade," Watson said. "Certainly a repeat diagnosis of colon cancer can be a blow to the family, but there are still many options."
Whatever the case, however, Watson said that in all likelihood doctors would not be able to completely eliminate Snow's cancer, and he would be put on a continuing chemotherapy regimen to keep the disease in check.
With an arsenal of cancer therapies available to oncologists today -- and treatments offering more hope on the way -- doctors today are able to deal more effectively with recurrent cancer than ever before.
"Most oncologists view colon cancer as more of a chronic disease, especially in patients who have a recurrence," Watson said.
But so far, it is impossible to ensure that a cancer will not resurface once it has gone into remission.
"You can't prevent recurrence from happening," Schoetz said, adding that for the time being, the best way to deal with the possibility of recurrence is to complete all recommended courses of chemotherapy and adhere to regular screening.
"Colon cancer and breast cancer are both extremely common cancers in this country," Schoetz said. "These are both diseases that have pretty intensive screening programs to find precancerous lesions."
This means that annual mammograms and colonoscopies can go a long way in detecting potential problems early -- a crucial step in managing any cancer.