It involved 603 people in Massachusetts, New Hampshire, Connecticut and Texas. All had failed chemotherapy for advanced cancer and had life expectancies of less than a year. They were interviewed at the start of the study and are being followed until their deaths. Records were used to document their care.

Of the 323 who have died so far, those who had end-of-life talks were three times less likely to spend their final week in intensive care, four times less likely to be on breathing machines, and six times less likely to be resuscitated.

About 7 percent of all patients in the study developed depression. Feeling nervous or worried was no more common among those who had end-of-life talks than those who did not.

That rings true, said Marshall, who is Mulligan's doctor at Georgetown University's Lombardi Comprehensive Cancer Center. Patients often are relieved, and can plan for a "good death" and make decisions, such as do-not-resuscitate orders.

"It's sad, and it's not good news, but you can see the tension begin to fall" as soon as the patient and the family come to grips with a situation they may have suspected but were afraid to bring up, he said.

From an ethics point of view, "it's easy — patients ought to know," said Dr. Anthony Lee Back of the Fred Hutchinson Cancer Center in Seattle. "Talking about prognosis is where the rubber meets the road. It's a make-or-break moment-you earn that trust or you blow it," he told doctors at a training session at the cancer conference on how to break bad news.

People react differently, though, said Dr. James Vredenburgh, a brain tumor specialist at Duke University.

"There are patients who want to talk about death and dying when I first meet them, before I ever treat them. There's other people who never will talk about it," he said.

"Most patients know in their heart" that the situation is grim, "but people have an amazing capacity to deny or just keep fighting. For a majority of patients it's a relief to know and to just be able to talk about it," he said.

Sometimes it's doctors who have trouble accepting that the end is near, or think they've failed the patient unless they keep trying to beat the disease, said Dr. Otis Brawley, chief medical officer at the American Cancer Society.

"I had seven patients die in one week once," Brawley said. "I actually had some personal regrets in some patients where I did not stop treatment and in retrospect, I think I should have."

James Rogers, 67 of Durham, N.C., wants no such regrets. Diagnosed with advanced lung cancer last October, he had only one question for the doctor who recommended treatment.

"I said 'Can you get rid of it?' She said 'no,'" and he decided to simply enjoy his final days with the help of the hospice staff at Duke.

"I like being told what my health condition is. I don't like beating around the bush," he said. "We all have to die. I've had a very good life. Death is not something that was fearful to me."