The branch of medical science that deals with prevention, diagnosis and treatment of tumor and cancer is known as oncology. Oncology consists of three main divisions that include medical oncology, surgical oncology and radiation oncology. Cancer is the uncontrolled and abnormal growth of cells .The factors responsible for cancer includes tobacco, alcohol, obesity and age. Its symptoms depend on the site and type of the cancer such as breast cancer, lung cancer, ovary cancer, cervix cancer etc. Diagnosis and treatment of cancer depends upon the site and type of cancer. The treatment of cancer includes surgery, chemotherapy, radiation and targeted therapy.