Breast cancer is the most common cancer among women, striking more than 215,000 women each year. As treatment has improved, death rates from the disease have decreased, and today about one out of 33 women who receive the diagnosis dies of the disease, according to the American Cancer Society.
Stephen F. Sener, president-elect of the society and a surgical oncologist at Northwestern University in Illinois, said a great deal will depend on the size and spread of the tumor.
Elizabeth Edwards is "resolute" about beating her breast cancer and then "moving on with her life," a longtime friend says.
Video: Elizabeth Edwards Diagnosed With Breast Cancer
If it is relatively small, perhaps less than 2 centimeters, and limited to one spot, he said, the most likely course of action would be a lumpectomy followed by about six weeks of radiation. Much larger tumors often require removal of the breast, called mastectomy.
A lumpectomy is most often followed by radiation, Sener said, based on a large, randomized clinical trial in the 1980s that found that without radiation therapy, the risk of recurrence increased from 4 percent to 40 percent. Some women undergo chemotherapy or hormone therapy after surgery instead of, or in addition to, radiation.
"She's at an age where she could get a recommendation for any of the three," he said.
The five-year survival rate in women with early-stage breast cancer who have radiation treatment and chemotherapy after surgery is between 73 percent and 81 percent, depending on the details of the treatment and the cancer, according to one large study. When the cancer has not spread to the lymph nodes in the armpit, the five-year survival rate approaches 90 percent.
Edwards's doctor in North Carolina recommended several specialists and urged her to see one as soon as possible. Anania said he is not aware of any history of cancer in the family.
Tricia Arnett, a friend who spoke to Edwards by phone yesterday morning, said, "She wanted to see the election through."
The Edwards family is familiar with adversity. In 1996, the couple's son Wade died in a car accident at age 16. The experience prompted John Edwards to leave a lucrative legal career and run for the Senate in 1998, while Elizabeth Edwards left her job as a lawyer to raise daughter Cate and later give birth to Emma Claire and Jack.
The family returned home to Washington on Wednesday night.
More than most political wives, Edwards seemed to revel in the excitement of the campaign trail and was often praised for remaining authentic through the heady experience. A brunette who has struggled with her weight, she jokingly refers to herself as the "anti-Barbie."
The couple celebrated their 27th wedding anniversary this summer the same way they have every year: at a Wendy's restaurant, the site of their first date. But this time, a 17-vehicle caravan of Secret Service agents, media and entertainers tagged along.
At one point during the campaign, Anania urged his sister to get some rest, to which she replied, "Rest is overrated."
Staff writer David Brown contributed to this report.