Cancer pain: From the development of mouse models to human clinical trials

Cancer-associated pain can be present at any time during the course of the disease, but the frequency and intensity of cancer pain tends to increase with advancing stages of cancer. In patients with advanced cancer, 62%–86% experience signicant pain, whichis described as moderate to severe in approximately 40%–50%and as very severe in 25%–30% (van den Beuken-van Everdingen et al. 2007). Bone cancer pain is the most common pain in patients with advanced cancer; two-thirds of patients with metastatic bone disease experience severe pain (Coleman 2006; Mercadante and Fulfaro 2007). Although bone is not a vital organ, many of the most common tumors (breast, prostate, thyroid, kidney, and lung) have a strong predilection for bone metastasis (Figure 4.1). Tumor metastases to the skeleton are major contributors to morbidity and mortality in metastatic cancer. Tumor growth in bone results in pain, hypercalcemia, anemia, increased susceptibility to infection, skeletal fractures.