Causes of pain Tumor:(1 tumor compression and invasion to adjacent organs tissue, nerves, bones or blood vessels or metastasis. (2) inflammation caused by tumor-induced mediators(e. g, interleukin, bradykinin) and so on Treatment-related: (1 Postsurgical pain syndrome(eg thoracotomy, mastectomy, amputation surgery, surgical scars and nerve damage). 2 Postchemotherapy pain (eg, polyneuropathy, osseous necrosis, thrombophlebitis and mucositis).3 Postradiation pain(eg, local damage neural fibrosis, medullary lesions bone necrosis and mucositis)Causes of pain • Tumor: ① tumor compression and invasion to adjacent organs, tissue, nerves, bones or blood vessels or metastasis.② inflammation caused by tumor-induced mediators (e.g, interleukin, bradykinin) and so on. • Treatment-related: ① Postsurgical pain syndrome (eg, thoracotomy, mastectomy, amputation surgery, surgical scars and nerve damage).② Postchemotherapy pain (eg, polyneuropathy, osseous necrosis, thrombophlebitis and mucositis).③ Postradiation pain (eg, local damage, neural fibrosis, medullary lesions, bone necrosis and mucositis)