Not long ago, a diagnosis of melanoma might well have been a death sentence for Jimmy Carter.

Because of great strides in treatment in recent years, however, there is hope of living with melanoma as a chronic disease, Carter and one of his doctors said Thursday.

Later today, he is scheduled to receive his first radiation treatment for four small tumors in his brain. He will undergo that treatment at Winship Cancer Institute of Emory University, whose executive director, Dr. Walter J. Curran Jr., is one of the nation’s leading radiation oncologists. Carter said a radiation “mask” — a device to hold his head in place so the radiation can be targeted as closely as possible to where it needs to go — already has been made for him.

“I get my first radiation treatment this afternoon,” a smiling Carter told a large group of reporters gathered at the Carter Center for the announcement.

Carter has become “quite a student of cancer,” Curran said in an interview after Carter’s comments.

Indeed. Carter did not even stumble over the pronunciation of the recently approved drug -- pembroluzimab -- that he is being treated with.

'It was the clinic you didn't want to go to'

The five-year survival rate of melanoma, an aggressive cancer that typically begins on the skin and spreads to other tissues, has reached 91.5 percent, according to the National Cancer Institute's surveillance unit.

Doctors who treat cancer said that some of the most important advances in their field in the past five years have come in the treatment of melanoma, which is a cancer of the skin.

“When we look at the big cancer meetings we have every year, the most exciting news recently has been about melanoma,” said Dr. Alan Bryce, a medical oncologist at Mayo Clinic Arizona who treats melanoma.

When cases are caught early — when the disease is localized — the survival rate is even better — 98.5 percent, according to cancer survival data from the National Cancer Institute. (The five-year survival rate is the measure most often used by cancer statisticians.)

That is a huge advance from decades ago, when melanoma could kill within weeks. Baby Boomers who love football may remember the story of California quarterback Joe Roth. Thousands of Georgia Bulldogs fans got to see Roth play in Sanford Stadium in fall, 1976. In February, 1977, Roth was dead from melanoma. Doctors thought that removal of a mole from Roth’s skin had cured him of the disease, but it returned vengefully in December, 1976.

For years, melanoma remained as close to a curse as there was in the cancer world.

“When I started my training (in 2003), it was the clinic you didn’t want to go to. There were no treatments,” Bryce said.

Immunotherapy drugs become integral

Treatment entered a new era in 2011. That’s when a new drug from Bristol-Myers Squibb was shown to extend the lives of people with melanoma. The drug, ipilimumab, rallies one’s own cells in a process called immunotherapy to fight the disease. Since then, two other drugs that use immunotherapy have been approved. As recently as 2014, the FDA approved a new immunotherapy drug called nivolumab. The drug used to treat Carter was approved only recently as well but has shown great promise, Curran said.

The radiation technique to treat Carter is also new, Curran said.

“Years ago, a patient would have had to receive full-brain radiation, and that can be tough,” Curran said. Now, however, radiation therapy techniques are so advanced that Curran and other  radiation oncologists can very precisely focus the radiation where it needs to go, sparing nearby tissue and uncomfortable side effects.

Curran said there is no cure for many metastatic diseases, such as metastatic melanoma.

“We’re not looking for cure in patients with metastatic melanoma, but we are looking to treat it as a chronic illness,” Curran said, noting that many diseases, such as high blood pressure, can be managed successfully for years.

In addition to those three drugs, three others that target mutations in a gene known as BRAF also have won approval.

“They lead to tumor shrinkage in about 90 percent of patients,” said Bryce. “So we have six new drugs that we didn’t have in 2010. It’s an entirely new landscape.”

All six drugs are used to treat metastatic cancer, or cancer that has spread to other organs as in Carter's case. His melanoma has spread to his brain and liver, he said Thursday.

Sunlight remains a key danger

About nine in 10 cases of melanoma are caused by exposure to UV radiation, according to the Centers for Disease Control.  Carter said his doctors were not certain where his originated.

From decades of living in the Deep South, Carter no doubt has spent much time in the sun, especially during his years as a peanut farmer.

Melanoma, which begins when cells called melanocytes malfunction, typically first appears to be a mole. It will look different, however, from other moles according to what doctors call the "A-B-C-D-E's" of moles: area, borders, color, diameter and  evolution.

The disease will be diagnosed in about 74,000 people this year, according to the Surveillance, Epidemiology and End Results Program, or SEER, a division of the cancer institute. That represents about 4.5 percent of all diagnosed cases of cancer for 2015, according to SEER.

People who have fair skin that freckles easily, who have blonde or red hair, or who have blue or green eyes are most at risk. Carter has fair skin, blue eyes and his hair was blond as a younger man. Having several large moles, having been sunburned badly early in life, being white and having a family history of melanoma are all risk factors.