Cancer is a major burden of disease in the world

Cancer is a major burden of disease in the world A term of cancer can define as diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymphatic systems. There are several types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukaemia is a cancer that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord also called malignancy. Cancer is a major burden of disease in the world. Each year, tens of millions of people are diagnosed with cancer around the world, and more than half of the patients eventually die from it. In many countries, cancer ranks the second most common cause of death following cardiovascular diseases. As elderly people are most susceptible to cancer and population aging continues in many countries, cancer will remain a major health problem around the globe. (national cancer institiute, 2016) It is usually not possible to know exactly why one person develops cancer and another doesn’t. But research has shown that certain risk factors may increase a person’s chances of developing cancer. Diet, Obesity, Tobacco and disease screening are important lifestyle practices that increase cancer risk, Cancer harms the body when altered cells divide uncontrollably to form lumps or masses of tissue called tumours (except in the case of leukaemia where cancer prohibits normal blood function by abnormal cell division in the blood stream). Tumours can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function. Tumours that stay in one spot and demonstrate limited growth are generally considered to be benign. More dangerous, or malignant, tumours form when two things occur: A cancerous cell manages to move throughout the body using the blood or lymphatic systems, destroying healthy tissue in a process called invasion That cell manages to divide and grow, making new blood vessels to feed itself in a process called angiogenesis. When a tumor successfully spreads to other parts of the body and grows, invading and destroying other healthy tissues, it is said to have metastasized. This process itself is called metastasis, and the result is a serious condition that is very difficult to treat. There are some general signs and symptoms associated with cancer. They are fatigue, lump or area of thickening that can be felt under the skin, weight changes including unintended loss or gain, skin changes, such as yellowing, darkening or redness of the skin, sores that wont heal, or changes to existing moles, changes in bowel or bladder habits, persistent cough or trouble breathing, difficulty swallowing, hoarseness, persistent indigestion or discomfort after eating, persistent unexplained muscle or joint pain, persistent, unexplained fevers or night sweats. Cells can experience uncontrolled growth if there are mutations to DNA, and therefore, alterations to the genes involved in cell division. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform. Not only that but also it tells how to grow and divide. Errors in the instructions can cause the cell to stop its normal function and may allow a cell to become cancer. Four key types of gene are responsible for the cell division process: oncogenes tell cells when to divide, tumor suppressor genes tell cells when not to divide, suicide genes control apoptosis and tell the cell to kill itself if something goes wrong, and DNA-repair genes instruct a cell to repair damaged DNA. Cancer occurs when a cells gene mutations make the cell unable to correct DNA damage and unable to commit suicide. Similarly, cancer is a result of mutations that inhibit oncogene and tumor suppressor gene function, leading to uncontrollable cell growth.A gene mutation can instruct a healthy cell to these things. They are allowing rapid growth, fail to stop uncontrolled cell growth, make mistake when repairing DNA errors. Allow rapid growth means a gene mutation can tell a cell to grow and divide more rapidly. This generate many new cells that all have that same mutation. Fail to stop uncontrolled cell growth means normal cells know when to stop growing. Therefore, we have just the right number of each type of cell. Cancer cells lose the controls. It tells them when to stop growing. A mutation in a tumour suppressor gene.