Explaining marginal benefits to patients, when "marginal" means additional but not necessarily small

Patients and their families want us to be realistic, honest, and caring about their prognosis and their options, even when the news is bad. Most oncologists will tell a patient if he is not curable, but not give specific survival information unless prompted. As an example, chemotherapy for pancreas cancer improves survival and does not worsen quality of life, but the impact on lifespan is small. Patients with advanced pancreas cancer have options that increase their average survival by about 16/100 at 1 year, and by about 9 weeks compared with best supportive care, but almost all patients are dead by 24 months. As an example of "marginal benefit" ("marginal" is defined here as more than that offered by the alternative care, not necessarily small or worthless), erlotinib added to gemcitabine compared with gemcitabine alone improves survival by six additional people at 1 year, and an average of 2 weeks, with no survival tail. In addition, the additional drug cost alone can be more than $12,000 a month. We use this clinical practice as a way to describe marginal benefit to patients. Telling patients that they have incurable disease and that treatment is ineffective is hard. Partly as a result, only about a third of cancer patients are told they are going to die, and those who are not told live no longer but have worse medical outcomes, such as dying on a ventilator and less time with hospice. These difficult conversations can be done if the oncologist has the right medical information, the right script, and some decision aids.