"There is hope," Balducci said, "provided that we provide the right treatment with the right patient. As we say: personalized treatment."
Others echoed the importance of a deeply individualized care management plan.
"It's not the calendar. It's not the years they've lived," said Dr. Len Lichtenfeld, deputy chief medical officer at the American Cancer Society. "It's the quality of life they have, their physical status and what they choose to do for the remaining years of their life."
He added, "Whenever you consider someone of President Carter's age, it's always a balancing act, and there are always many factors to consider as you decide what the best thing is for that particular patient."
In his new book, "A Full Life: Reflections at Ninety," published in July, Carter wrote: "There was no record of another American family having lost four members to this disease, and since that time I have had regular X-rays, CAT scans, or blood analyses, with hope of early detection if I develop the same symptoms."
Hallie Jackson is the chief White House correspondent for NBC News.