Understanding and managing cancer of unknown primary.

As a nurse, it is important to understand, and to be able to meet, the informational needs of patients and their family caregivers. Comprehensive information can help to reduce the fear of a challenging diagnosis. In the case of cancer of unknown primary (CUP) it may be helpful to understand some of what is unknown as well as what is known of this phenomenon, which represents some 5% of cancer diagnoses (Pentheroudakis et al, 2007b). Drawing on the literature, this article focuses on definitions, characterization, categorization and treatment of CUP.