Open communication in cancer care has gained increasing importance in recent years and diagnostic disclosure is now common place. However, there is a significant variability in the sharing of prognostic information. Information needs may vary significantly over the disease trajectory, and there has been relatively little work done focussing on late illness. Using systematic review procedures, 13 studies were identified that addressed this issue. The evidence shows that all patients wanted honesty from their professional team and the vast majority wanted some broad indication of their prognosis, but that preferences for quantitative information were more varied. Benefits associated with realistic awareness included enhanced control and end-of-life planning, which was seen to engender hope. However, for a proportion of patients, hope and realism were irreconcilable when presented with detailed or unequivocal information. Professionals have a responsibility to provide information to patients, but also to respect the need to maintain some ambiguity about the future, if that is a patient's wish. Therefore, prognostic discussions necessitate careful, individualised assessment, a process which can facilitate enhanced palliative care for patients with advanced cancer.