TUESDAY, June 3 (HealthDay News) -- Sen. Edward M. Kennedy enjoyed "a restful night's sleep" and was walking the hallways of Duke University Medical Center on Tuesday, one day after undergoing what his doctors called a "successful" three-and-a-half-hour surgery to treat his malignant brain tumor.

The 76-year-old Kennedy was "recuperating well from yesterday's procedure," his office said in a statement released to the Associated Press. "He is experiencing no complications and has been walking the hallways, spending time with family and actively keeping up with the news of the day."

"He looks forward to returning home to Cape Cod soon, and is thankful for all the prayers and well wishes," the statement said.

No further updates on Kennedy's condition were expected until he leaves the Durham, N.C., hospital, according to the statement. He is expected to remain at the hospital for about a week before heading to Massachusetts General Hospital in Boston for radiation and chemotherapy treatments.

The surgery was performed by Dr. Allan Friedman, neurosurgeon-in-chief at Duke and one of the nation's leading neurosurgeons. "I am pleased to report that Senator Kennedy's surgery was successful and accomplished our goals," Friedman said in a statement released Monday, the Boston Globe reported.

Friedman said Kennedy had been awake during the operation and "should therefore experience no permanent neurological effects from the surgery," the newspaper said.

Asked by his wife, Vicki, how he felt after the surgery, Kennedy said, "I feel like a million bucks. I think I'll do that again tomorrow," the senator's office said, the Globe reported.

Kennedy underwent surgery for a malignant glioma, an especially lethal type of brain tumor. The surgery was considered the most aggressive approach that Kennedy could select to treat his tumor. The decision to opt for surgery was considered something of a surprise, the Globe reported, because Kennedy's doctors did not mention surgery as an option after the tumor diagnosis was announced two weeks ago. Instead, Kennedy's doctors said the focus of treatment would be radiation and chemotherapy.

Specifics about Kennedy's particular type of tumor haven't been disclosed. Some cancer specialists said the tumor appears likely to be a glioblastoma multiforme -- a serious and tough-to-remove type -- because other kinds of brain tumors are more common in younger people, the AP reported.

Still, cancer experts said Kennedy faces a difficult struggle.

"In the more aggressive gliomas, the outlook is not good," said Dr. Leonard Lichtenfeld, deputy chief medical officer at the American Cancer Society. "This is a serious situation with a difficult outlook."

Dr. Eugene Flamm, chair of the department of neurosurgery at Montefiore Medical Center in New York City, said a patient with this type of brain tumor typically dies in about a year. "Some patients will die in less than a year, and others may live for two years," he said.

"No matter where the glioblastoma is located, it's not curable. When I talk to patients, I don't talk about cure. I talk about trying to control the tumor," Flamm said.

Dr. Ania Pollack, a neurosurgeon at the University of Kansas Hospital in Kansas City, agreed. "Life expectancy for a man Senator Kennedy's age with such a tumor is about 12 to 14 months," she said.

While there hasn't been much improvement in survival, there are experimental treatments, Pollack noted. These include immuno treatments and targeted chemotherapy and local radiation therapy, she said.

In fact, a study presented Monday at the American Society of Clinical Oncology annual meeting in Chicago reported that an experimental cancer vaccine is showing promise against the same general type of brain tumor diagnosed in Sen. Kennedy. The vaccine, when given with chemotherapy, more than doubled progression-free survival in patients with glioblastoma multiforme tumors -- from 6.4 months to 16.6 months.

Discussing Kennedy's post-surgery care, Flamm said radiation and chemotherapy are the usual course of treatment. Patients also typically receive anti-seizure medication, he noted.

"Radiation usually takes about four to six weeks," Flamm said. "While every protocol is different, chemotherapy is usually repeated every eight weeks if you are getting a response."

Whether Kennedy will be able to return to work in the Senate is not clear. "It's not just the physical part of it, it's a psychological burden. If Kennedy feels he wants to do it, he should do it," Flamm said. "I would think he'd have to wait until the end of radiation therapy. So, it would be several months."

The American Cancer Society estimates that 21,810 malignant tumors of the brain or spinal cord will be diagnosed this year in the United States. Approximately 13,070 people -- 7,420 men and 5,650 women -- will die from these malignant tumors. The cancers account for about 1.3 percent of all cancers and 2.2 percent of all cancer-related deaths in the United States.

The first evidence that a person has a malignant tumor is often a seizure like one Kennedy suffered last month, or stroke-like symptoms. Kennedy, the second-longest serving Democratic senator in Congress, suffered a seizure May 17 while at his family's Hyannisport, Mass., compound and was taken by helicopter to Boston.

In October 2007, a partially blocked carotid artery in Kennedy's neck was discovered during a routine magnetic resonance imaging (MRI) examination. Doctors cleared the blockage, and Kennedy was released to convalesce in Hyannisport.

Kennedy is the youngest of nine children, and became a U.S. senator in 1962. His older brother, President John F. Kennedy, was assassinated in 1963. Another brother, Robert Kennedy, who was also a U.S. senator, was assassinated in 1968 during his presidential campaign.

More information

The U.S. National Library of Medicine has more on glioma.