The aim of this chapter is to present an overview of cancer pain, pain assessment and pain management.

Cancer pain is arguably one of the most common symptoms reported by cancer patients (Lang and Patt [120]). The prevalence of cancer pain has been estimated at 39.3% after curative treatment, 55.0% during anticancer treatment and 66.4% in advanced, metastatic or terminal disease (van den Beuken et al. [225]). Despite this high incidence of pain and advances in moderate treatment methods, up to 50% of patients continue to be undertreated (Deandrea et al. [50]) with 67% of patients reporting their experience of pain as distressing (Breivik et al. [20]). This high incidence of untreated pain results in a reduction in patient quality of life and can impact on the regular activities of daily living (Portenoy [174]).