PURPOSE: To describe characteristics, outcomes, and decision making in patients with colorectal cancer metastatic to the liver, and to examine the relationship of doctor-patient communication with patient understanding of prognosis and physician understanding of patients' treatment preferences. PATIENTS AND METHODS: The Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT) was a prospective cohort study conducted at five teaching hospitals in the United States between 1989 and 1994. Participants in this study were hospitalized patients 18 years of age or older with known liver metastases who had been diagnosed with colorectal cancer at least 1 month earlier. Data were collected by patient interview and chart review at study entry; patients were interviewed again at 2 and 6 months. Data collected by physician interview included estimates of survival and impressions of patients' preferences for cardiopulmonary resuscitation (CPR). Patients and physicians were also asked about discussions about prognosis and resuscitation preferences. RESULTS: We studied 520 patients with metastatic colorectal cancer (median age 64, 56% male, 80% white, 2-month survival 78%, 6-month survival 56%). Quality of life (62% "good" to "excellent") and functional status (median number of disabilities = 0) were high at study entry and remained so among interviewed survivors at 2 and 6 months. Of 339 patients with available information, 212 (63%) of 339 wanted CPR in the event of a cardiopulmonary arrest. Factors independently associated with preference for resuscitation included younger age, better quality of life, absence of lung metastases, and greater patient estimate of 2-month prognosis. Of the patients who preferred not to receive CPR, less than half had a do-not-resuscitate note or order written. Patients' self-assessed prognoses were less accurate than those of their physicians. Physicians incorrectly identified patient CPR preferences in 30% of cases. Neither patient prognostication nor physician understanding of preferences were significantly better when discussions were reported between doctors and patients. CONCLUSIONS: A majority of patients with colorectal cancer have preferences regarding end of life care. The substantial misunderstanding between patients and their physicians about prognosis and treatment preferences appears not to be improved by direct communication. Future research focused on enhancing the effectiveness of communication between patients and physicians about end of life issues is needed.