"Affecting at least 50 million individuals at an annual cost of $70 billion, chronic pain poses a significant health burden in the United States. While therapy for cancer pain has improved dramatically over the past decade, treatment of nonmalignant chronic pain remains a challenge for many practitioners and patients.Narcotics are known to be effective in malignant pain, and are a mainstay in the palliative care of cancer patients." (Quoted from article)