Pathophysiology and clinical characteristics of pain in most common locations in cancer patients.

Pain is one of the most common symptoms in cancer patients, especially in advanced disease. However, pain also accompanies a significant percentage of patients during diagnostic and therapeutic procedures. In some patients pain may be the first symptom of the disease. The causes of pain in cancer patients are often multifactorial including direct and indirect cancer effects, anticancer therapy and co-morbidities. Moreover, pain in cancer patients often has mixed pathophysiology including both nociceptive and neuropathic components, especially in patients with bone metastases. In this article, basic knowledge regarding epidemiology, pathophysiology and clinical features of pain in cancer patients with a primary tumour localised in lung, gastrointestinal tract (stomach, colon and pancreas), breast in women and prostate in men are presented. Pain is a common symptom in cancer patients and its appropriate assessment and treatment may significantly improve in patients' and families' quality of life.