Chronic pain in cancer patients

Background. Pain is a complex clinical sign that is highly variable in both intensity and perception by patients. Often, a combination of symptoms and signs can indicate a pain syndrome specific to oncology. Virtually all patients with malignant diseases experience recurrent episodes of acute pain, which may accompany previous surgery, invasive procedures, or complications such as pathologic fractures or disease progression. Chronic pain is a huge economic burden on society, both in terms of health care and lost productivity.Effective treatment of chronic pain results in significant improvements in general and psychological wellbeing and functioning of cancer patients and reduces the burden of chronic pain on health services.The purpose is to clarify the problems of the prevalence of chronic pain in cancer patients, the complexity and variability of the pathophysiological mechanisms of the development of pain syndrome, to consider modern approaches to the management of patients with chronic pain.Materials and methods. Modern foreign guidelines for the management of cancer patients with pain syndrome, written in English, data from metaanalyses, reviews and clinical studies were used.Conclusions. Data from a 2016 crosssectional study to determine the prevalence and impact of depression on health care costs in patients with complex chronic pain indicated that patients with chronic pain are at increased risk of developing depressive disorder of varying severity. About onethird of the study sample had major depression, and the overall prevalence of depression among individuals with chronic pain was higher than 50% [3].Up to 75% of all cancer patients with chronic pain have nociceptive (somatic or visceral) or neuropathic syndromes, which are a direct consequence of the development and progression of the neoplasm. Other causes include anticancer drugs and disorders unrelated to the disease or its treatment.Several systems are used to classify the pain syndrome, in particular — ECS-CP, IASP, ACTTION-APS.Today, in the management of cancer patients with chronic pain, the WHO threestep analgesic ladder is used: the first two steps are paracetamol and NSAIDs, mild opioids (control of mild and moderate pain), the third is opioids. The selection of opioids, their dosage and titration features should take into account the individual characteristics of the patient in order to avoid overdose and addiction.In addition to the abovementioned drugs, studies are being conducted to determine the effectiveness and feasibility of using medical cannabis as an alternative means, the use of which will improve the general condition of patients by relieving pain, and preventing the development of opioid addiction.Interventional techniques (neurolytic blockades, neuraxial infusions, trigger point injections, spinal cord stimulation, intrathecal drug administration, and vertebral augmentation) are also used to control chronic pain. The application of physical and psychosocial methods in the comprehensive management of such patients is studied.