1 There are over 200 types of cancer.  Anything that may cause a normal body cell to develop abnormally potentially can cause cancer; general categories of cancer-related or causative agents are as follows: chemical or toxic compound exposures, ionizing radiation, some pathogens, and human genetics.
Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. For some types of brain tumour you may have chemotherapy after surgery, to try to prevent the tumour from coming back. Chemotherapy is sometimes given with radiotherapy and for some months afterwards to help people to live longer.hemotherapy works very well for some types of brain tumour but it does not work for all of them. You may have some types of chemotherapy in cycles. You have the drugs for a few days every few weeks.
Or you may have it with another treatment, such as chemotherapy or surgery. For small cell lung cancer, you may have radiotherapy with or after chemotherapy. And you may also have radiotherapy to your brain. Treatment to the brain aims to kill off any lung cancer cells that may have spread there.or small cell lung cancer, radiotherapy is sometimes used with or after chemotherapy. Chemotherapy makes the tumour in the lung shrink. Giving radiotherapy as well improves the results. You may also have radiotherapy to your brain, which aims to kill off any cancer cells that may have spread to the brain.