Dr. Martha Twaddle talks to a patient and strokes her hair during a visit at the Midwest Palliative and Hospice CareCenter in Skokie, Ill., in 2012. Antonia Perez/MCT /Landov hide caption

itoggle caption Antonia Perez/MCT /Landov

David Oliver sits quietly as he waits for the results of a scan at Ellis Fischel Cancer Center in Columbia, Mo., in 2012. The University of Missouri research professor was diagnosed with cancer in September 2011. He broke the news to colleagues via a video on the Internet. Jeff Roberson/AP hide caption

itoggle caption Jeff Roberson/AP

Dr. Joel Policzer checks on his patient, Lillian Landry, in the hospice wing of an Florida hospital in 2009. A new study found that many terminally ill cancer patients don't fully understand their prognosis. J. Pat Carter/AP hide caption

itoggle caption J. Pat Carter/AP