Story highlights Patients, doctors and family members should talk over end-of-life treatment

Patients can go into hospice care if their prognosis for survival is less than 6 months

(CNN) Sen. John McCain and his family have made the difficult decision to discontinue treatment for McCain's terminal brain cancer. Legendary singer Aretha Franklin also decided to discontinue treatment toward the end of her life. How patients and families do this kind of risk-benefit analysis about end-of-life decisions involves a complicated and emotional conversation that experts say you should have as early as possible when someone is seriously ill.

Oncologist Dr. Otis Brawley said he still finds shocking a conversation he had 30 years ago with the daughter of a terminally ill cancer patient he treated. He remembers asking the daughter whether they should stick with what he called "reasonable care" for the woman.

"When I used that term, I was thinking about comfort measures, but the daughter told me, 'Dr. Brawley, everything is reasonable,' " he recalled.

But "everything" is not always the best option, said Brawley, the chief medical and scientific officer for the American Cancer Society.

"Then what typically happens is, you end up with a patient on a ventilator, in intensive care, with all kinds of drugs to support their blood pressure and other body functions," Brawley said. "The quality of that person's life for their final days is absolutely awful."