Cancer is the second most frequent cause of death, only exceeded by heart disease. Treatment of cancer includes chemotherapy, radiotherapy, and surgery.Radiation therapy can be given alone or in conjunction with surgery, chemotherapy or hormonal therapy. Some patients may require general anesthesia in order to have treatment with radiotherapy.The essay will cover the following subjects:-Hazards of use of chemotherapy.-Hazards of use radiation therapy.-Different paraneoplastic syndromes.-Cancer pain management.-Bone marrow transplantation.