Chemotherapy is treatment of cancer using drugs that kill cancer cells by interfering with their multiplication.It is available mostly as an intravenous formulation (drip). Some drugs also have oral preparations which are equally effective and convenient.
The side effects of chemotherapy stem from the understanding that chemotherapy kills actively multipying cells,like cancer cells. However other rapidly multiplying cells like the cells of the hair and gut, can get affected as "bystanders". These however recover once the treatment is completed.
The common side effects of chemotherapy are therefore hair loss, nausea and vomiting, constipation, fatigue,and mouth ulcers. It is important to note that none of these side effects are universal and your oncologist will discuss side effects specific to your chemotherapy regimen.
Other treatment modalities in the fight against cancer are hormonal manipulation,where the hormonal mileau is manipulated to treat some cancers or decrease the risk of recurrence after surgery and/or chemotherapy.
In recent years new drugs termed "monoclonal antibodies" have also emerged as an important treatment tool. These drugs are not chemotherapy,but interfere with cellular communication,thereby slowing down the growth of the tumour.
Radiation therapy is often used to treat patients with cancer. In contrast to chemotherapy it is a local treatment only and is used to treat disease that is localised to a specific area. Radiation therapy is delivered using photons which are 'packet of energy'. This energy is deposited in cells and causes the cells to die. Radiation kills both normal and cancer cells but normal cells are better able to recover than cancer cells and therefore there is a therapeutic advantage. Radiation therapy is normally delivered over a protracted period of time to allow the normal cells to recover.